If you are just starting out tying your own flies then this thread should get you started.

http://www.wildfisher.co.uk/smf/index.php?topic=15731.0

This must be the longest thread of flies in history. Started in 2008 it is still being added to. There should be a fly in it that takes your fancy :)

http://www.wildfisher.co.uk/smf/index.php?topic=9025.0

There are also two videos showing all the flies in the thread.