^ Really, a Pad is advisable. At the very least don't draw any conclusions about the game due to its shambolic keyboard controls/support without at least testing with a pad.
You will require the resolution rendering mod, available here:
http://www.neogaf.com/forum/showthread.php?t=488240 It will need .ini tweaking.
Also, go into this game in the full knowledge that it is still the 360 version.
Nothing has been optimised or altered in porting it to the PC, it's still locked to 30fps but they may change in time, mods permitting.
Once you get past these nuances, except Dark Souls for what it is, a bloody good game that everyone should experience at least once.
I'll pick it up again when it's on sale, I pumped too many hours in to the PS3 version to pass up, besides I would like to experience Blight Town at something more than 8fps.