If i wanna make my own ringtone from a 30-sec mp3, do i just put it onto a micro sd card and put it into my phone and set as ringtone or do i have to use a different procedure?

What I do is open up the mp3 in Audacity (free software sticky) then just select the section I want and go to edit > copy. Then I go to file > new > then paste the section in there. Then hit export > .mp3 (you'll need the "lame" exporter, I think it comes with the download now, if not just post and I can help you through that ).

If I remember correctly, the file also has to be below 300KB, so if the 30 second clip is too large, just export it again with a lower bitrate (even 64kbps is fine for a ringtone).

My ringtone is below 300 kb, and is exactly 64 kps but it won't show up on the sd card when i put it into the phone

It has to be under the Audio > Tones directory of the SD card.

If it doesn't then your phone may not support MP3 files - it may need to be a MIDI or something similar.

EDIT) Stupid flood control...