If you've been ttc for that long with no results, then you and your partner both need to see a doctor to rule out that there's a problem preventing conception from occurring.
In the meantime, you're at a fertility charting board, so I would be remiss if I didn't recommend that you chart your cycles so you will know when you are most likely to be fertile and can time your bd accordingly. I recommend the book Taking Charge of Your Fertility by Toni Weschler.
Here are some other links that you may find helpful:
http://parenting.ivillage.com/ttc/ttcsex/topics/0,,4rwv,00.html
http://www.ivillage.com/fertilityplanner?o=dcm,fp,iv,el,fptopic,pp,lnav
The Trying to Conceive message board might also be a good place to hang out.
