Where to find proven design patterns?
A good place to start would be the Reference Design Library at AllAboutCircuits.com

It has a large searchable database of common circuits.

Another option is more vendor specific.  For instance Texas Instruments has nice tools for helping design typical circuits.

Even Digi-Key has a good reference library.

If you are looking for more basic/fundamental circuits, I think you would be best off with a book such as The Art of Electronics.