Dark Souls

Great solutions so far. Where do I get a good divine weapon/upgrade materials?

In order to upgrade to a divine weapon, you need to get Andre of Astoria--that's the smith in the Undead Parish basement--the Divine Ember. You get that in the tower after beating the Moonlight Butterfly in Darkroot Garden. Conveniently enough, you can get to this boss fairly quickly -from- Andre, provided you can manage to either sprint past or defeat the Prowling Demon down the stairs from the smith.

To deal with said Prowling Demon, sprint along the right side of the room as fast as you can or, if you're feeling froggy and want to fight him, position yourself behind his left arm next to his body and you'll be safe from pretty much all of his attacks except his jump attack--which you'll want to sidestep or roll out of the way of. He's weak to fire, if you happen to have a fire weapon.

Past this chamber you'll want to follow the narrow pathway through the wilderness and past a stretch of cliffs fighting tree people--they're pretty easy to deal with, just make sure you don't get close enough that you let them grab you, which they telegraph with a big 'gimme a hug' animation. Once you're past all of them, you'll find a big mystical door to which Andre sells the key for 20,000--but that's not where we're headed; you can, however, attack the wall to the left of this door to reveal a hidden bonfire, which could be pretty helpful.

Continue down the path to the right of the bonfire to find a fog door and head on through, taking care to avoid a tree convention ambush. In the next area, hug the left wall mostly and make your way around to the ruins on the far end of the courtyard; a stone giant will start to wake up, but you can sprint past him and should for now--they're a bit of a pain in that they can slow you down to where you can't run, roll, etc. and then hammer on you. Up the stairs, you'll find another fog door from which you'll be able to see the butterfly hanging out on a tower nearby--that's the tower the ember and other goodies are in.

Fighting the Moonlight Butterfly is probably the easiest boss fight in the game--and if you've got a shield with good magic resistance, you can basically trivialize it. None of the attacks are particularly tricky, just a lot of projectiles with loose homing that you can generally roll beneath when they get close to you. Every now and then, the boss will land on the wall inviting a melee oriented character to go two-handed with their weapon and beat on them for a while. Generally, you should be able to finish them off by the third landing--claiming the Moonlight Butterfly soul and then trucking up the stairs for your divine ember.

Once you're situated with that, what you're looking for is some Green Titanite Shards. There's a lot of places you'll just start finding these as treasure past around The Depths (sewers under the Undead Burgs)--I can't recall exactly where, but I know I found my first shard in the regular course of looting treasure down there and made my weapon off of that. Green Titanite Shards drop off of the slimes in the Depths (somewhat rarely) and the giant slugs in the Blighttown Swamp (when they do drop there, they drop in stacks of 5 though--very convenient! And the slugs are pretty easy to kill).

As an alternative to all of this, if you've got the Master Key as your starting gift then you can sneak into the Valley of Drakes from the New Londo Ruins elevator and sneak/suicide rush past some drakes to find the Astoria Straight Sword, which is a divine weapon off the bat--but I'm of the opinion that making a more skeleton-suitable weapon for your divine pick (seeing as how it's mostly skeletons you want divine -for-) to be more worthwhile.

Also, if you've got the Master Key and head to the Valley of Drakes, you can take the little bridge across to Blighttown for a shortcut--riding the water wheel elevator down both for quick access to Queelag's Domain and the boss there--and access to the giant slugs of the swamp on the far end, in order to scrounge up some Green Titanite Shards if you're inclined.

Personally, I made a divine halberd since the regular thrust crumples skeletons essentially stun-locking them and the heavy attack is a big crowd controlling skelesweep.

This was a lot longer than I'd expected, so sorry for wordiness--but hopefully this helps cover everything to get you kitted out with divine.