I know how to learn how to read and write Japanese via Core 6k and sentences. My question is how can one learn to speak? I'm in high school and there aren't a lot of native Japanese speakers near me. How should I go about practicing my speech?

Put an add on craigslist asking for a tutor.

Same with local paper.

Skype

Sharedtalk.com

I suggest self-talk, as presented here:
http://tiny.cc/mac57

I also recommend my recent video on pitch accent:

If you can, getting a language partner can be very valuable. Even if you think there aren't many Japanese people, place an ad in Kijiji or Craigslist, whichever is more popular in your area. If you feel gutsy, write to a language school where Japanese students go. Surprisingly, that worked for me.

If you want to practice pronunciation you could try shadowing too.

if you want to do it for freee

listen to lots of japanese and check out youtube. lol

there are helpful youtube vidoes like tofugu did a videon the R sound in japanese
http://www.tofugu.com/2009/12/30/how-to-...e-r-sound/

and recently I came across this girl on youtube

Her R sounds sound so japanese native lol.

Thank you all. I tried shadowing, and it worked pretty well. I watched the video on pitch accent too, and I found it pretty helpful.

@howtosavealif3
My parents probably won't spend money for me to learn japanese (they aren't that enthusiastic about it), but I'll watch the videos ASAP.

This book　has quite a lot of good drills and exercises:

http://www.amazon.co.jp/%E3%82%B3%E3%83%...4883192954