u.s. masters forums have a lot of great workout tips, but remember, these workouts are based on a 25m/yd length pool
Workouts - U.S. Masters Swimming Discussion Forums
for actual stroke techniques and suggestions i'd just google around the different exercises you see that you don't really understand.
if you never really received proper training for flip turns, there are some good online resources. the turn should be from the abs, not the arms (both arms should be down by your hips when you start your turn). more turns, more abs