Bukavu is a beautiful city with five fingers stretching into Lake Kivu, separated from Rwanda by the Ruzizi River. Eastern DRC is an unstable region, so check with your local embassy for travel advice. The Panzi Hosptial is situated here.
You can reach Bukavu from Rwanda via the borders of Cyangugu (Rwanda), from Burundi via the border of Uvira, and from Goma via Lake Kivu or by road. Do not approach expecting to be able to buy a visa at the border. Have it beforehand and also be prepared to wait. It's just one fellow writing everything down in a big ledger. Remember to smile and people are usually nice.
Expect to pay $10 - $50 to travel by road to Goma depending on speed / comfort. The expensive boat from Goma is quick and comfortable. If you're white you may have to argue to get a cheap ticket, apparently it's 'not suitable for tourists'. Remember to keep your passport on your person.
There are wooden boats to Idjwi island leaving at various times through the day. Ask around at the port. Unlike the northern part of the lake the water here is generally calmer (due to it being narrow and populated with a high number of islands) so the voyage by wooden boat is not usually unduly traumatic.
The roads in the Kivu region are not very good, but there's not much traffic. Traffic in Bukavu can get hectic, but is manageable. Do not use the moto-taxis after dark.
Kayaking along the fingers stretching into Lake Kivu is amazing.
Bukavu is mainly a dollar economy, so plan to use Congolese francs only for small purchases. For shopping, check out the SuperMarket Asante, between the Mayor building and SONAs, in front of the Bukavu Cathedral. Rather expensive, but great people.
For lunch and dinner, try the Cafe and Restaurant Asante at Supermarket Asante, located between the Mayor Building and SONAS.
If you want to get out Bukavu City: Please visit Kaziba about 35 mileages (55km) from the big city Bukavu. There is a guest House at Byakweli's property, closer to the Kaziba Hospital.