Hanoi is a very pleasant place to visit and live. It has not yet been taken over by automobiles (but that is in the process of happening). Five years ago, the great majority of Hanoians got around on bicycles, with maybe 20% people using motorbikes. Nowadays, probably 80-90% get around on motorbikes, 10% use bicyles (mostly students), and the number of cars on the road is rising rapidly. Occasionally you might even see a Hummer trying to squeeze between the motorcycles. Unfortunately, there are almost no parking lots in Hanoi for cars (motorbikes just park on the sidewalks, but in a very organized and efficient way. Parking (and guarding) your motorbike downtown for pretty much as long as you want will cost you about VND 1,000 (US$0.06).
An epicurian's delight, Hanoi has everything from the highest end Vietnamese, French and Italian restaurants to ubiquitous sidewalk restaurants on every corner, which serve delicious pho ba, ga and ca (beef, chicken, fish soup) for about fifty cents for a large bowl, so come hungry. There are many sidewalk cafes where students and (mostly) young working people go. It almost has a feel of cafes in Paris where people (mostly young men) sit and drink coffee and chat and smoke cigarettes. Larger foreigners might have a hard time sitting on the little plastic stools, which result in your knees being about chest-high when you sit down. Vietnamese food has a widely known and well-deserved reputation as being excellent, and very healthy (lots of veggies, and not so much salty fried food like in Indonesia). Don't worry about getting sick from eating the raw vegetables and salads here. After three years here eating just about anywhere, I have never gotten sick. It's not like India or Nepal, where you sometimes take your life into your hands when eating anything other than very well-cooked food.
The best museums are the Museum of Ethnology (there are many ethnic tribes in the highlands of Vietnam, who have very different cultures and languages from the majority Kinh people), and depending upon what you were doing in the late '60s and early '70s, the Army Museum on Dien Bien Phu Street. It gives a fascinating view into both the French and then the American War (that's what people call it here). Interestingly, almost no one here still harbors any animosity towards Americans about the war, whether it's the more urbane city folks, or the peasant farmers out in the countryside. Maybe it's because, after all, they won. Stop by the Hoa Lo prison for half an hour to see what it was like for the Vietnamese revolutionaries trying to reclaim their country from the French colonialists, and look at the pictures of the people that were gullotined. There is a real guillotine there as well.
The Fine Arts museum is not that interesting, but there are many high quality art galleries on and around Tran Tien Street, which is downtown near Hoan Kiem Lake. In many ways the center of Hanoi, Hoan Kiem Lake is a very pleasant place to take a stroll, as do many Vietnamese, especially early in the morning or after the heat of the day. For arts and crafts (shops are everywhere downtown), Vietnamese wood carvers are among the finest in the world. Wood carvings of dragons and phoenixes and turtles are equisite. If you want to impress your friends, you can buy an almost perfect replica of virtually any famous work of art for $15–20 from the little art shops on Hang Trong Street. They charge by the size of the painting, and depending upon the workload, it usually takes a week or so if you commission a specific painting. The art shops all have illustrated art books you can choose from, or just take you pick from many websites they can easily show you.
Getting around Hanoi is easy and cheap on a motorcycle taxi. Rides of a couple of kilometers are about 10-20,000 Vietnam Dong (VND), or about US$0.70 to $1.50 (VND 16,000 = US$1 these days). VND 10,000 will get you just about anyplace, but negotiate first. Metered taxis are about five times as much. It is a wonderful place to walk around, but you must watch the traffic patterns very carefully to see how the motorbikes navigate when you are crossing the street. 95% of the motorbike drivers are very respectful of pedestrians (and usually especially cautious when they see a foreigner trying to cross the road). However, beware of the crazy motorcycle speeders (not surprizingly, 99% are young men 16-25) who weave in and out of the traffic, and cause many accidents. People routinely run red lights if the coats is relatively clear, even old ladies on motorbikes and school kids on bicycles. People often drive on the wrong side of the street if it is convenient, until they see a chance to cross over to the correct lane. Taking a left turn from the far right side of the road across several lanes of traffic seldom solicits a honk from other drivers. Turn signals are used very sparingly, if at all. Even if you are sued to riding a motorcycle, the trick is to stay with a pack of people going your way, avoid being a lone rider, drive slowly, and don't get angry when people don't follow official traffic rules.
Get up at 5:30 in the morning and ride down to the area where Ho Chi Minh's mausoleum is. There are hundreds of people (many old and middle aged) doing their morning exercises (whether aerobics, badminton, or just walking backwards - which is considered th eperfect exercise), many with portable music boxes to dance to. One of the interesting things that many Vietnamese do is ballroom dancing. There is a government office across the street from me where several nights a week people gather to learn the waltz, cha-cha and even a little swing dancing. Many government offices have ballroom dancing classes after work.
You can buy just about anything you want in Hanoi. For example, in the last few years the number of shops selling a wide range of good quality Australian and French wine has increased dramatically. The locally made wine (mostly from Dalat) still has a way to go in its development cycle, but the high end stuff (there are three kinds at three prices) isn't bad.
There are some excellent massage places here, but you have to know where they are. There are several excellent places out in the Tay Ho area that cater to the many expats who live there. Not surprizingly, there are far more funky massage / karaoke places that provide little more than a quickie. As a general rule, if you want a good massage, don't bother to try and find one in a hotel (unless you want to pay a lot for a good massage in a 4-5 star hotel).
Compared many large Asian cities (e.g., Manila or Jakarta), to Hanoi is a relatively low-crime area, but like any big city, there are some places to avoid (e.g., where the heroin dealers making their living under the Long Bien Bridge over the Red River). Just use good sense about where you go, and you shouldn't have any major problems. Generally, people here are quite friendly and willing to help you out when you get lost, or are looking for a particular place. Unfortunately, except for young educated people, not many people yet speak English very well, although that is changing quickly, as the abiltiy to speak English is an almost guaranteed ticket for getting a good job here. If you speak Russian, you shouldn't have much difficulty talking to many people over 50, at least the government folks, many of whom were educated in the Soviet Union during and after the war. Out of six, Vietnamese is the most difficult language I have ever tried to learn (it's the tones - the grammar is easy), so don't expect to be able to pick it up in a couple of weeks (or even months) visit.
Although the weather is often rainy and cold then, visting Hanoi in the week or two before Tet is probably the most interesting time of year. The large streets sprout instant markets for people to find the perfect quat tree, or peach blossom branch, and everyone is out cruising along on their motorbikes, window shopping. Imagine a two meter high tree loaded with cumquats strapped on the back of a motorbike. Then imagine literally hundreds of motorbikes driving down the street with quat trees and peach blossoms. In what is one of the most photogenic countries I have ever lived in or visited, this is the most photogenic time of year.