[...] I still haven't figured out exactly how to refill my canteen.
HogDriver, you can refill your canteen by walking into the water of the coast or a pond. Click the middle mouse button and you should be able to select to refill your canteen. Just make sure to not walk too far into the water. It's said that the player loses his backpack when walking into deep water. Also, as per some player diaries, there ought to be water pumps around where the player is able to refill his canteen.
Another tip for those having trouble playing at night (personally, I somehow prefer it): turn brightness and gamma all the way up. You'll get what I'd like to call "cat-vision", which really helps spotting zombies and other players.
Also I found that even though some players might shoot you at sight, there are generally a lot of very helpful people around on the servers. So, simply ask when you have a question or need translation of a Cyrillic name sign of a place (beware though, this of course also gives away your position to bandits).
Last but not least, there's a "Newbie Survivor Guide
" in the official forum that might be helpful.