I'll start with the best tip for when you do find one - shoot it so the bullet will go through the lungs in between the shoulders because the lungs don't really extend very far behind the shoulder. Javelina anatomy is different than deer anatomy - if you hit a javelina with a classic deer behind the shoulder shot, you've probably shot it too far back (ask me how I know ;)). Once you have one down on the ground, make sure it is dead (touch it with your gun muzzle from behind). Some people will tell you erroneously that you need to cut out the scent glands on the javelina's back - that's wrong - just leave the scent glands alone, and they will come off with the skin when you skin the javelina. Just don't touch the scent glands (they're near the hams/back legs) with anything - your hands, knife, or anything else, and you'll be fine with regard to the scent glands.
Regarding finding them, it depends on the terrain. If the terrain is such that you can glass for them with binoculars, using your binocular is a good technique. I've hunted them by spot and stalk (in Arizona and West Texas) and by baiting on senderos (in South Texas where there wasn't terrain for glassing). I'll tell you I MUCH prefer the spot and stalk.
One nice way to do spot and stalk is to have a "big eyes" (e.g., 15x58) binocular mounted on a tripod - that is a very comfortable way to cover a lot of ground - with your eyes rather than with your feet.
Here's a website that will help you learn more about javelina hunting:
JavelinaHunter.com 
