Welcome to TalkChelsea. Your best place to start for info on tickets is to look at the official website, Chelseafc.com. There's a section on up and coming fixtures which gives you details on when you can buy tickets. You'll need to almost certainly have to register as a member, it's only £25. As to where to sit, I'm still learning, i'm sure some of the other guys can advise. I think Matthew Harding or Shed End would be good if you want the atmosphere with the singing. I've been advised as a new member to sit in the West Stand to get a feel for the ground, which is OK if you just want to sit and watch the match and sing the occasional song.