I don't know how you parents will be, becasue everyone's different, but mine were just fine. I couldn't bring myself to actually tell my mom outloud (i'd come out to my friends via-e-mail and hadn't then said it to anyone but myself), and so showed dher a poem i'd written a couple months before stating i was gay. then i let it all sink in for awhile before actually talking to her about it, but she's been very supportive of me, and is trying very hard to understand, tho i'm not always sure that she gets it.
my dad i had assumed for awhile knew (i asked my mom not to tell him cause i wanted to do itwhen i was ready, but didn't exactly hide it from my dad), but then right before valentine's day asked me if i had a 'special boy', and i told him that i never would, but might have a special girl someday. he got a funny look on his fface, said he hadn't known that, and fell silent. A few minutes later he got up and left, hardly saying a word to me the rest of the night. since then he hasn't actually talked to me about it, but has acknowledged my sexuality indirectly.
anyway, my point is that it can be very difficult, but i think it's really worth it--but, then, it turned out fine for me, so who am i to say?
if i were u, i basically just wait till the point where i felt comfortable enough to where i'd be okay with them reacting badly. if u think that your parents won't be okay with it, you may first want to practice telling others you lknow that you think may not like it, to see if you think that u could handle ur parents' rejection.
anyway, i hope i was helpful, and i guess if not, i got a chance to vent some of my own stuff!
good luck coming out
grosses bisses
~jas