http://www.trainforstrength.com/exercises.shtml
I found some great info on this site.
My workouts include (very cheap)
-Pushups
-hindu Pushups
-Many bodyweight squat variations, including trying to work my way up to doing pistols
http://www.powerathletesmag.com/pages/pistols.htm I have a ways to go yet
-many variations of chinups and pullups. I have a bar I put in my bedroom door (just a wooden dowel supported by 2 squares of wood with a U cut in them to hold the bar) and I do pullup variations on a painter's ladder which is set up to be four feet high and 8 feet across.
-a lot of lowerbody hamstring a glute work can be done on the ladder too
-sprints on stairs
-different dips and "thingies" that I do using a couple of plastic handlebar type things I found for 10 bucks in the store.
-lunges
-when I feel like it, barbell rows, stiff leg deadlifts, dumbell swings.
-hiking, sometimes with a loaded backpack. This, of course takes terrain, heavy boots and a heavy duty pack.
There are so many things you can do without purchasing expensive equipment!! The nice thing about a lot of body weight exercises, or "bigger" exercises such as squats and lunges is that they don't isolate specific muscle groups, you use many other muscles for stabilization.
If you want any explanations or more ideas let me know
I'm not bodybuilding. If you want to specifically bodybuild you will definitely want specifics like a barbell, a dumbell, plates, a bench etc. but strength training and getting a strong and fit body with good muscularity does not require much at all. Equipment wise, it will take effort!!
You may want to do a few searches for things like renegade training, bodyweight training... a lot of martial artists and gymnasts use bodyweight exercises and calisthenics. I find them very integral and more difficult than one might imagine!