If you have even a small space to workout, you can do plenty with a couple of dumbbells, a sandbag, medicine ball, etc.
I recommend
Infinite Intensity. It's inexpensive, and he shows you how to make a homemade dumbbell setup (also inexpensive) that will allow you to do a lot. It's got a good mixture of conditioning, strength, and bodyweight workouts in there. But, it shows you how you can stay basic and get a great workout routine going.
I workout in my garage whenever I have my kids over or are short on time to hit the gym. All I've got out there is a sandbag (25-160lbs), three db handles and enough weights to go to a single db of 130lbs, two medicine balls, jumprope, etc.
The duffelbag for the sandbag is the most expensive part of that.
The dbs cost about $100 to $150 in the end, but I just started with a Walmart db set ($35 for 40lbs) and a few extra 10lbs plates ($5 each). So, for $55, you have 80lbs to play around with. That's plenty of weight for most people to start with when you put it all on one handle.
I have a school nearby for doing pullups/chinups, but adding one to a doorway or garage wall is pretty cheap.
This one doesn't require tools and is portable.