First of all Welcome to PPCGeeks.
Take a look at these WM Guides:
WM Guide for All Levels
It might help you get started.
As for music I personally like PocketMusic. For Pics I have both SBP Imageer and Resco Image Viewer and even though I usually tend to like SBP software in a lot of situations, I like Resco Viewer more.
In the WM guide link above check out the Must Have article and see some of the Today Screen apps there.
I hope this helps.