Talk and talk to NPC's, talk to them after you've talked to others or done a boss or events; read item descriptions. There's more there than you'll ever realise.
Anyway, my speed run isn't going well although a lot better than first attempt. Survived Valley of Drakes for red tearstone ring and killed BK but didn't get the halberd drop, just the BK shield. Carried on and farmed for Quad's favourite, which is now at +5 and contemplating a drop into Blightown...
Bearing in mind the Speed runner did Blightown in about 2.5 mins, I'll be happy with under 15 mins