Refresh yourself best by shooting, shooting and shooting, once of course you have learned what features are available to you and how to get to them on the camera. The core principles aren't all that different from SLR to DSLR and the advantage is that you can shoot till your eyes bleed to get down a technique or 10 without having to pay a photolab a penny for practice shots. Plus the exif data means you don't need to spend as much time taking notes in a book of what your shooting/learning.
Another thing would be to carefully think through your storage or archiving of images. I have tons of images from doing multi-media presentation along with a good number of my own digital photos. There was never a good system implemented when I started and that simply put translates to a mess on my harddrives. Might I suggest
The DAM Book: Digital Asset Management for Photographers
The book itself covers a primary workflow from the camera to your archives, from there you can modify. The site has a forum and the topics cover some variants to the books workflow. Even if you don't adopt the whole process it is indepth enough to allow you to work out your own system with your own preferred tools.