I recently went through all my old journals (more than 20 years worth), and learned a few things.
Don't go digital unless you're okay with potentially losing all your stuff. I have about 6 Zip disks full of old notes and readings. Thing is, I went to a Mac platform about 6 years ago, and converting those files (even just to print them) is a huge PITA. It may not be an issue now with things like Dropbox and iCloud, but be prepared.
Spiral notebooks, although not necessarily pretty, are pretty darn handy for keeping track of things like daily draws and readings you do for yourself.
If you take notes when you read, or go off on tangents with things you want to add to your reading practice (geomancy? astrology? gypsy cartomancy?) go with a loseleaf notebook. You can add, subtract, and most importantly, rearrange things with ease. I found these awesome notebooks about 8 years ago, and LOVE them.
Instead of buying pre-punched paper, get the portable punch- much cheaper in the long run.
http://www.levenger.com/Circa-Notebook-Shell-5849.aspx
It is pretty cool to be able to look at old journal entries and readings from years ago and see how my interpretations of things have evolved. So, definitely keep writing it all down.