Estelí is a city in northern Nicaragua.
There are two bus stations both on the Pan American about 100m from each other. The southern is smaller and better organised but more buses come and go from the north. Most main destinations are served by both though so you will need to check both for times etc. Both stations are a little out of the main town (C$15-C$20 in collectivo to the Parque Central 2007). You could try a long dusty walk along the Pan American turning left at the only set of traffic lights on the road until you bump into the main south/north route to the plaza.
Local buses (C$3 to any destination) and share taxis (C$8 in the central area and no more C$20 within the city, agree on the price before you get in). You can easily walk around the city center.
Lots of beautiful murals in various places around town.
Visit Miraflor, an agricultural cooperative a couple of hours outside of Esteli in the mountains. There are a number of places at Miraflor where you can stay in cabins or with families, ride horses, meet farmers, looks at orchids, etc. Visit Hospedaje Luna (below) for more information. Dona Corina's place is well liked; US$17 gets you a bed and 3 meals a day.
Tisey is a nature preserve just south of Esteli. Take a city bus to the hospital, and then a local bus up the mountain or catch the bus to Tisey at the Cotran Sur on the Pan American highway. On the way up, you can stop in Estanzuela and see a waterfall. The water looks too dirty for swimming and there's lots of garbage everywhere (Nov 2007). But worth the trip.
Further up the road is La Garnacha, a community consisting mostly of organic farmers plus a factory of some amazingly good cheese. To visit, you need to get off the bus at the La Garnacha sign and walk up their road about 2km. From there, if you are still up for a hike, you can walk to and climb up Cerro Apaguají. It is on private property but open to the public. It's about another 1km of hike from La Garnacha. From the cerro you can see Lake Managua to the south, the chain of volcanos along the Pacific and, on a clear day, part of El Salvador on the other side of the Gulf of Fonseca.
Learn Spanish: There are several Spanish schools around town. When foreign volunteers would come to Esteli to help the Sandinistas they would often study in Esteli. Escuela Horizonte  is a respectable one : $220 a week for 3.5 hours of instruction, excursions and homestay with a local family including 3 meals a day (at least two of which will be gallo pinto; and beware of the local queso, it's not too popular among foreigners).
The Esteli region is also home to many fine cigar companies, most of whom will allow a prearranged tour, and some of whom offer special package tours of their factories (Drew Estate, in particular).
There is a public market in the south end of town. Easy to find or just ask. Just north of that market are lots of leather shops. Good stuff at good prices. For example, you can probably get a custom made pair of boots for around US$50.