Bro, i'll give u some really good advice - if you feel that you'll get tired against all the opposition - to make things simple - simply paste a really user friendly, easy going Islamic site which is trustworthy behind you - so even if you never check that site out again - you know that you've left a link behind which others can benefit from if they're interested.
a good example of that type of site is: http://islamreligion.com
Then just run away and continue in sharing the site to other forums, its much easier this way and much more beneficial i think.
By the way, you should also meet up with other du'aat to get tips off them, and to unite in the same purpose of dawah - that's why we created this site: http://idawah.com
I think using the first idea is the most effective insha Allah :)