I assume by your question that you're an aspiring young designer maybe in school yet?
Membership in local "user-groups" for Photoshop, InDesign, etc or design guild (if there is one in your area). Make the time to go to meetings and get involved, make connections that might pay-off one day. Design and print your own business cards to hand-out at these meetings from places like
OvernightPrints. Join
NAPP or get a subscription to
Communication Arts or other top design publications. Books are okay, but I'd rather get hands-on, so maybe set aside the money for training seminars or special classes put on by design industry gurus.
As far as stuff goes, calibrator is a great idea, a decent scanner is handy, tablet or high-resolution mouse.
Another thing would be investing in a portfolio, but not a traditional one. Design a booklet-style port that you have printed up through Apple iPhoto or Shutterfly (there are many services you can do this at today). It's nice to be able to hand one of these to a contact face-to-face rather than hoping they'll look at your website or PDF later. Yes, you can save-out a PDF version of it too, but I find looking at a printed port shows that person understands investing in themselves is a sign of a quality designer and worker.
Otherwise, you can't go wrong with fine chocolates!
