Hi undead lee,
I've been coming to this forum for a while to read what others had to say without creating myself an account. I have been playing for Dark Souls for a while now, but I never completed one play through yet; mostly due for my need of perfection where I start a new game 15 to 20 hours of game play.
I decide to create an account on the forum to give you a few more tips and answer your questions, cause I had a lot of them when I first started playing.
Just to clarify, PvP means Player versus Player and PvE is Player versus Environment. So basically, online versus single player for most games, but dark souls is different in many ways.
Humanity, among many thing like scaling damage on certain weapons and item discovery rate, basically allow you to regain humanity which is extremely important for co-op and online play.When your humanity count (upper left corner of your screen) is 01 or more, you may regain your humanity when resting at a bonfire and selecting "Restore Humanity" (or something like that). Being human will allow you to invite player to your game to help you out (co-op) by summoning white soapstone signs on the ground. Those white marks are normally around bonfires and near boss' fog wall. If you regain humanity, you should be able to see a few of those soap marks around the Bell Tower Guardian, for example. The white soap stone will also allow you to put down your white mark on the ground for someone else to summon you. You don't need to regain humanity for another player to summon you, just put your soapstone sign down.
If you regain humanity, BE CAREFUL! this will also allow other players to invade your world in order to kill you. If you get killed, you start at the bonfire like any other death no big deal, they steal a few souls and you are once again a hollow (You can't get invaded if you're hollow). If you summoned another player to your world, they may help you if you get invaded, but from what I saw on this forum, they don't always feel it's "Fair" to help out a player who is being invaded. I saw screw that, if I get summoned, I help in any way I can! Enough about humanity, you'll figure out the rest I'm sure if you didn't already know it.
You did manage to find the Burg on your first play through, kudos on that. On my first play through I had the master key and headed toward Blight town and I was wondering why the game was so freaking hard.
What I recommend to you, is to stay as far away from the elevator that brings you to the New Londo Ruins and don't even think of going in the catacombs (that place still scares the crap out of me). Even if you don't want to kill the Bell Tower Guardians right away, you should of acquired the basement key. That key will allow you to access Lower Burg. Remember the Dragon that spits fire on the bridge just after you killed the first boss "Taurus Demon"? Well there is a door that you may open with the basement key. I don't want to give you too much details as it is the fun of the game to discover these things, but once you go down there is an easy shortcut that brings you back to the first bonfire in the Burg. Good Luck!
You have a lot of easy places to visit (Lower Burg, Darkroot Garden, Darkroot Basin, The Dept, Blightown, Sens Fortress, etc.) before you even thing of going back to the Catacombs and New Londo Ruins. Of course, this game has very few mandatory bosses and paths, so you are free to explore which ever way you want!
Lastly, the weapons! Good job upgrading your weapons right away. Later in the games you will have a lot of souls to buy titanite shards, so don't be scared to use them early in the game if you can. What I have learned while experiencing Dark Souls' weapons is that there are no best weapon. Every weapons works as good as you can use them. The Claymore and Halberd are good weapons, but are heavy and make you stumble around after each hit. In other word, they are slow to recover which leave you open against fast enemies (like the Bell Tower Guardians). You can always take the cheap route and use the Drake sword, but real men don't use that sword in the early game. If you want a good fast weapon, kill the Undead Merchant in the Burg, He drops a Uchigatana, which is quick and scales very well with the amount of Dex you have. Won't hit as hard as your Claymore, but you will get a lot more hits in before you have to get the hell out. I still use a +5 Lightning or +15 Uchigatana late in the game.
Anyway, best part of Dark Souls is the feeling you get after accomplishing something you've been dying over and over again. Experiencing with everything is key in this game!!
Sorry if I gave information you already knew, but hopefully a few things in here will help you out.
Now that is one long first post...
Long live Dark Souls!