Get a silcock key. I've got a 4-way one that I turned into a smiley with some rope.
Look into water-filters. I've got a Sawyer mini. They're great, just don't let it get under 32 Fahrenheit or it's trash.
Get a decent rain poncho, from army surplus or whatever, that unsnaps into a tarp.
Do a little research on sock options for hiking/long trecks and decide what's best for you.
On the cheap, pantyhose will wick sweat away, and so keep you dry. I like the ones that just come up to the knee, cause they're easier to put on or pull off. They'll also help keep blisters away, cause they'll act as an inner sock.
In general, try to start with as few things as you can when you start. You can always get that extra thing later, but if you get it now and and then find out its really not worth the weight, well you just waisted resources.
Read backpacking magazines and internet forums. Get on Reddit. They've got tons of great forums. Also, definitely use the search on this website. Check the forum on here dedicated to food, and the one on gear, and the one on work.
And after you've perused all the sources that are available to you, come back here or other forums (like Reddit) and ask more specific questions.
Good luck.
