Deadlifting is good, and can be done with no extra equipment. Squats while holding dumbells or kettlebells would work too. You could also do good mornings, which is basically bending at the waist with a bar on your shoulders. Before you do any new kind of exercises though, I'd at least get one session with a trainer to go over form. ( I never did, but wish I had, many times )
I just googled some dumbell/barbell stuff and came up with
Workout Questions - Weekly Dumbbell Workout Plan
Click the links and they have some vids of the various exercises and suggestions for different stuff to try.