(Written before noticing heyvern's good advice...) The tutorials included with the programme are the best I've seen. I'm a n00b too and learnt the basics through those. Other third party tutorials tend to be more technical and advanced. My suggestion would be to go through the tutorials slowly and c...

Firstly, are you using the right tool? The bone transition tool will stretch the body around, but the bone manipulation tool will let all the bones moves around eachother like ... well, like a sketeton. Secondly, maybe you could fiddle wth bone strength. Maybe the bones' regions of influence are too...