Okay, to get to your ignore list, what you have to do is this, go to your profile and click the "Customize Profile" button, that'll take you to the User Control Panel, on the left hand side, you'll see all the places you can go to on your control panel, scroll down to the "Settings and Options" tab, and at the bottom of that tab, you'll see "Edit Ignore List."
Click on that and it'll come up with a text box that tells you to enter the name of the person you want to ignore, type in the name of the member, then click the "Okay" button next to it and you'll be sorted.
Sure, I'll add you on XBL, just know that I'm not much of a multiplayer gamer, I only really play when the mood strikes me, I only buy Gold because I like the colour, that, and I usually find myself wanting to play online more when I don't have it.
Still, if you send me a game invite and I'm playing something like Oblivion or Prototype, I'll usually be with you within about 30 minutes to an hour.