Well damn, everyone already went and covered the big points, so I'll just throw in some little tidbits and be on my way:
1)grab a shortbow and some arrows. Not to kill anything with, god no, but to aggro enemies. If you can keep as many enemy encounters down to 1 v 1 fights as possible, you'll have a much higher survival rate.
2)take your time, check your corners (especially when passing through doorways), and keep your shield up when entering new areas just in case.
3)if you encounter a boss for the first time, it's probably best to just accept that whatever souls and humanity you have stocked are forfeit. If you can manage to keep them then great, but otherwise just accept it and move on. You'll find more of both.
4)don't spec yourself as a pure-magic user. It seems great at first, but you WILL get fucked later in the game.
5)if you have nothing to lose anyway, try doing a few suicide-runs through areas to find items. Sometimes you'll find nice things.
6)the starting area has a path leading through a graveyard and a path leading up the side of a cliff. Stay the hell away from the graveyard, that's a path to take later in the game. If you don't mind doing suicide runs though, there are some nice things hidden in that graveyard if you can get to them.
7)personal preference for this one, but I'd say to stay away from the drake sword. It makes the first portion of the game a bit of a joke, true, but in doing so it robs you of skills and knowledge you can use later in the game to avoid frustration. The sword simply does not scale well, and will become obsolete with very little warning. If you were relying on it to hack through enemies, it can leave you in a position where you don't really know what you're doing and don't have any weapons to fall back on. That's just how I saw it and I avoided it on my first playthrough. Everyone's different though.