For the best $ value lodging, I recommend Sunbreeze Hotel, around $100-$120/night, clean, roomy, fresh water pool, bar, rinse shower, foot baths, ice machine, air conditioning, wonderful ocean view and a restaurant $$, on site. They provide bottled water in the pitcher. Sometimes the tap water has an odor, but we have not had a problem from drinking it.
For diving, BottomTime Divers, around $40 for a two tank dive. Rudy Duran is my favorite divemaster there. They have rental gear, if needed. They only take small groups and have very good boats with canopies.
For economical food, Ruby's, Celi's Deli, Tropic Take Out (breakfast & lunch only) across from the air strip, and Erika's at the street vendors location near Central Park, across from the Church. All of these are very inexpensive and good. Everyplace we have eaten has been good food, only some are more expensive.
As far as the friendly people are concerned, You will NEVER, EVER meet nicer or friendlier people. The people are the main reason we return to San Pedro as often as we can. We came for the diving and stayed for the people and the view.