colored hair with highlights? OMG how?

hello,

Before you ask, yes i am a bit of a fool. I know nothing
in the ways of the hair color or the bleach, so please
could someone help me?

Firstly, i am a guy(that explains the foolishness) with 2-3 inch long darkish brown hair. At the moment, ive got
it in a slightly messed up sticking up in front sort of look
(on purpose) and im going for a change in style.

Basically, i want to go a medium, natural blond but also
to have some lighter blond highlights on top/ bleach the
tips on top.

>> Trouble is, i really dunno how to do this:
to lighten my hair i presume i`ll have to bleach and then color my hair to get the blond, but to get highlights or
bleached tips wouldnt i have to bleach again?
Does bleach bleach colored hair?

I`m really confused! Please help!
Thanks
Jon