From a tourist point of view San Borja is nothing special apart from a necessary stopover on the way to San Ignacio de Moxos or Trinidad. However, the town has seen a large influx of people in the last 50 year, multiplying the local population by over 5 times.
From Rurrenabaque, take two shared taxis to San Borja, changing in Yucumo. Each leg is around 2 hr and cost around Bs. 70-80 each way. You can get a shared taxi directly from Rurrenabaque (via Yucumo) for Bs. 80; takes 2h 30 min. Rurrenabaque to Yucumo is asphalt (with holes), and Yucumo to San Borja is an impressive dirt road.
Otherwise, frequent buses travel between Rurrenabaque and La Paz. Get off in Yucumo and take another one from there.
An alternate way would be to fly into Trinidad and carry on by land.
The bus (and shared taxi) terminal is at the edge of the town. Take a mototaxi to travel between the two.
Moto taxis (motorcycles) or the occasional real taxi.
Central square has elements painted yellow with red, which makes for a warm and positive impression.
Locals spend weekends out of town (possibly in the nature) - ask them where and how.
There are some stalls in bus terminal that sell basic food and drink.
- Hotel San Borja - on the main plaza. Rooms about 25b a night with shared bathroom. Kind of dirty, owners are kind of Slum-lordish. Loud when the ubiquitous celebrations in the Plaza occur at all times of day or night. The bathrooms upstairs don't work and you must go downstairs to use an ugly one. DO NOT give them laundry to do; they lose things.
- Hotel Avenida - about 8 blocks from the main plaza heading towards the airport. About 20 beds a night with shared bathroom. Tranquile.
- Hotel El Bosque, Calle Oruro between Santa Cruz and Potosí streets, ☏ , ✉ firstname.lastname@example.org. Decent hotel with garden with OK Wi-Fi, but make sure to get a room with ceiling fan or air conditioning.
Some say straying more than a few blocks from the main plaza at night is dangerous.
Internet is generally slow and on slow machines that cost Bs. 10/hr. Telephone calls to the U.S. are a bit steep.
- San Ignacio de Moxos – A town that has a nice church and well-known local traditions, which can be traced back to Jesuit missions.
- Trinidad – A pleasant town, which has a couple of attractions itself, and can serve as a gateway to more places in Beni, e.g. Riberalta and smaller places in between. More - you can take a multi-day boat ride via Mamore river starting from near Trinidad and up to Guayaramerín at the border with Brazil.