First, everything here is a generalization. "Most guys" means most guys, not all guys. With that in mind...
Most guys are very different than women, when it comes to what they enjoy. With women, starting out very slowly is more important. With guys, there is a much better chance that the guy will be impatient, and there is most definitely a lower overall standard as to what most guys will enjoy.
When starting out, the best bet is to start slowly, and indirectly. Men tend to be more visual than women, stereotypically, so part of taking your time would include almost touching...kissing around the rest of his body (depending on what's accessible under the circumstances), caressing, but not necessarily actually touching his erotic zones, yet.
When doing this, remember the "many guys get impatient" rule. The longer you can drag out each step (while still making progress), the better, but some guys don't want much of this at all, and if you pay attention it should become obvious.
Unfortunately, another general difference is that guys are less expressive. This is a shame, because it keeps them from enjoying it as much, as well as making it harder for you to tell what works with them. I cases like that, talking about them perhaps being more expressive, especially by telling them it excites you (hopefully this is true), is the best bet...but only if your relationship (or their personality) is secure enough to allow it.
The other day, on Don & Mike (radio gods), a woman caller bragged that her nickname was "eight seconds", meaning the time it took her to bring a guy to orgasm from fellatio. While a sizable portion of guys do actually like that, it...