Just make sure that the session is approached as an experiment, and that neither of you brings to it unrealistic expectations of immediate, spectacular success. Nobody's born knowing how to do this sort of thing, at least not until those replicants get here.
If you two get this far and wish to oh heck, there's no better way to put this go a little deeper, there's good information to be found in instructional videos and DVDs, like the ones Nina Hartley puts out, and in books such as Violet Blue's The Ultimate Guide to Fellatio, which contains nifty tips like how to keep your lipstick perfect throughout, as well as, yes, bona fide deep-throating techniques. I think deep-throating is overrated, myself, but then, I only borrow a penis and ought to defer here to those who possess them full time.
One last word of warning: Yes, there can be a somewhat unpleasant surprise at the end of a successful blow job. Inform him that he is responsible for early warning and withdrawal, no "whoopsies" allowed. This probably ought to be considered nonnegotiable at the beginning, subject to later review.
See Andrea's other column at carnalnation.com