Hospedaje Aventura (tel. 505/2252-2270 or 505/8871-5554, laposadasanjose [at] gmail [dot] com, www.laposadasanjose.com [1], $5/d with fan, some have a/c) has simple but really spartan rooms with ample sunlight on the second floor of a converted, family home.
The Bearded Monkey (across from the fire station, tel. 505/2552-4028, www.thebeardedmonkey.com [2], $6 dorm, $14 for a private room) is without a doubt, the backpacker set’s favorite, with dorm-style rooms and a laid-back, communal atmosphere. Expect cool music, an eclectic crowd, movie nights, and free Internet access. A few other places in town have successfully copied the monkey vibe.
Hospedaje Samarcanda (Calle la Libertad, five blocks west of the central plaza, tel. 505/2552-8069, www.hospedajesamarcanda.com [3], $6 dorm, $16–39 rooms) is farther away, but clean and decent, with breakfast.
Hospedaje El Chelero (two blocks west of the park, tel. 505/8379-2657 or 505/8955-2602, elchelerohostal [at] hotmail [dot] com, $5 dorm beds, from $8–15 private rooms with a/c) is locally owned and basic, in an unrenovated colonial home sporting brand new beds. They rent bikes, too.
Hostel Oasis (one block north, one block east of the market, tel. 505/2552-8005, www.nicaraguahostel.com [4], $6 dorm bed, $19–28 rooms) is one of the quietest in this range, with the bonus of a swimming pool, which matters. Travelers have reported surly staff and bedbugs here, so have a close look at the mattress before sealing the deal.
Hospedaje La Calzada (tel. 505/8475-9229, mariinez_1970 [at] yahoo [dot] com, $12.50 with private bath, $10 shared bath) has been around for over a decade at least; what it lacks in decor it makes up in location.
Hospedaje Cocibolca (Calle la Calzada, three blocks east of park, tel. 505/2552-7223, hospedaje_cocibolca [at] yahoo [dot] com, www.hospedajecocibolca.com [5], $18) has wireless Internet, friendly and professional service, and over ten years of experience.
Hostal Dorado (1.5 blocks west of the park on Calle Xalteva, tel. 505/2252-6932, info [at] hostaldorado [dot] com, www.hostaldorado.com [6], $25) comes well recommended, but not all the rooms have private bathrooms. A supermarket is across the street, which is convenient.
Hospedaje Ruiz (Calle la Calzada, tel. 505/2552-2346, $20 with private bath) has been around longer than some of the competition; rooms are simple but well ventilated and quite clean.
Similar but less experienced is Posada las Brisas (Calle la Calzada, tel. 505/2552-3984 or 8885-3989, tcristac [at] hotmail [dot] es, $20–25 with fans) is family-run, safe, and clean. Features include wireless Internet, refrigerator, and kitchen access but no air-conditioning.
Hospedaje La Libertad (three blocks west of park on Calle la Libertad, tel. 505/2552-4017, hospedaje_lalibertad [at] hotmail [dot] com, $8 dorm beds, $15/s with shared bath) offers dorm beds, but the dormitories are broad and well ventilated, and the bright colors are nice.
Links:
[1] http://www.laposadasanjose.com
[2] http://www.thebeardedmonkey.com
[3] http://www.hospedajesamarcanda.com
[4] http://www.nicaraguahostel.com
[5] http://www.hospedajecocibolca.com
[6] http://www.hostaldorado.com