How to bribe bloggers for coverage?

I think that bribing influential bloggers by sending them gifts can be a good way of obtaining coverage since it clearly differentiates you from the other email pitches. A $30 or so book is a lot cheaper than a hundred dollar adwords budget! What I don't know, however, is how to go about doing this. Does anyone have any suggestions? How do you find out where to mail the gift to, how to tactfully ask for the favor in exchange, etc.