Crockpots vary but low setting is typically around 100 degrees and its high setting is around 300 degrees.
Knowing this, it is fairly easy to convert most recipes for use in your slow cooker. Some adjusments to cooking times will be a judgement call on your part, but some simple guidelines should help. Just follow a few simple rules and you're on your way.
You should decrease liquid since it does not boil away in a crockpot.
Add cheeses and other milk product towards end of your cooking since they tend to break down if they are cooked for too long.
Brown any ground beef before adding to crockpot. It will taste better and have better texture this way.
Add rice and noodles at end of your cooking as well. They will turn mushy if they are cooked too long. You can cook these separately and then combine them when it's time to serve.