You might want to apply to adsense. Given your PR and traffic you'll probably get approved. They do have a rather long application process though so apply as soon as you can.

You might also want to try creating an amazon affiliates account. I've had some success with them.

If you're looking for a quick fix, infolinks might work. But I hate intext advertising because it's annoying to see all those links and popups when I read other people's stuff so I don't use them.

If you're interested in looking up some products that you can promote, try checking out clickbank and commission junction.

But before you decide on the affiliate stuff though (adsense and amazon you can just plaster on there anytime you want) really think about what you want your blog to become. Because it can get annoying for a lot of people/followers when they see ads that are there just for the sake of earning some money.

You've got a pretty good following and you'll want to keep and grow that. So be careful with the type of monetization you use.

If you're looking to learn about the subject before jumping in, check out Pat Flyn's stuff. He's got an amazingly useful podcast and he's always very honest about his stuff.

Plus he's not gonna try to sell you anything lol unlike a lot of the other "gurus" online. He'll maybe suggest something from time to time but he never does hard sell so he's easier to listen to and read.

Good luck.