Fm radio transmitter

hey guys any body could help me to build my own fm transmitter at 87.7 mhz or any other

That's a rather vague request. What do you need the device to do? I think you need to expand on your requirements a bit and tell us weather such a device may or may not be legal in your country. As you can imagine knowledege of your legal and regulatory systems is somewhat limited in the world at large.

Power output and range?
Mono or stereo?
Cheap junk or good quality?
If it uses British or American parts then can you get them?