Installed this the other day after seeing this thread and watching those videos. Spent alot of yesterday mucking about on it and talking to other players, asking questions etc. I have a few pointers I've discovered that might help newer players (like me).
Choose wisely - The server clocks are real time and linked to server location, so pick a server in a different time zone and you could find yourself very alone in the dark. This is bad. Very bad.
Zombies like houses - You wont find them in the middle of forrests and interestingly if you get chased into the woods by some Zombies they will drop dead if you get them far enough in... not sure if this is a glitch or meant to happen but it has become a used tactic for me a few times when I've needed it. I got chased by one zombie that quickly became two. I ran into the woods and could hear them chasing, after getting about 200yds in they just cried out and went silent. When I turned around they were dead.... all 15 of them (boy do they bring their mates when they see you!!)
Zombies hate noise - Don't shoot them unless you absolutely have to. The gunfire will attract other zombies very quickly (and they can move bloody fast once they know your there). It will also attract other human players who might be more willing to help the zombies in finishing you off than visa versa. There is nothing wrong with running away!!!
Lunchtime - Eat and drink. You will need it. However supplies are obviously very scarce so try to hold on for as long as you can before doing either as you don't know when you will find more food or a fresh water pond to refill your water bottle. If you run everywhere you will need to eat or drink sooner, so it's also worth pacing yourself when travelling.
Be a tree hugger - As above, zombies tend not to come near the forrests so use the tree lines to scope out possible raiding locations before just blundering in. This also hides you a bit from potential snipers and bandits.
Get down! - Zombies cannot see or hear you if you are prone unless they litterally fall over you. I got kinda cornered in a town yesterday and hadn't been spotted so I went prone and crawled out on by belly avoiding 20+ zombies on the way. You will go back to crouched if you access you gear or try to pick something up though, so best avoid doing this with zombies nearby. If they have already seen you dropping prone wont help, we spoke about the running away bit already?
Become your own Sat-Nav - With 225square Km it's very easy to walk for ages without seeing anything but trees and the odd farm, getting lost is very very easy to do. Roads are a good marker but these lead to zombies, so use the trees around them to move. A proper map is one of the hardest things to find in the game (hence the most valuable thing too... don't tell other players if you have one). If you really want to know where you are you can download a map from the web and make notes on it once you find a road sign. Once you do this you can plan where to go for possible loot/supplies and make note of bodies of water easier and maybe even plan your route accordingly.
Don't break your legs - The gravity and damage is highly realistic. If jumping from a particular height would break your legs in real life then it will also do so in the game. This is bad and WILL result in your eventual death as you slowly bleed out on the floor out cold. Especially bad thing to do if your fleeing from zombies at the time (yeah, found this out the hard way).
Health yourself up - As already stated the game does not feature any form of health regeneration (dead means dead). If your bleeding and loosing blood, use a bandage and maybe morphine. If you get injured you might start getting the shakes, eat something and maybe use your painkillers. If you have lost some blood you can replenish a tiny bit by eating but you can also (if you have found the items you need) give yourself a blood transfusion.
For a game with no missions, objectives or plot apart from simply staying alive this is completely addictive (providing you have the patience and like trees, lots and lots of trees).
If anyone else has some idiot guide tips please add them here... I need them too!!