Hey guys, I thought I'd just let you know that motion VFX is having a winter sale. Instead of mFlare being 109, its only 59 bucks. Its definitely worth your money. mFlare make the most professional, realistic lens flare ever. You can customize your own mFlare, or even use from the huge library of cool presets. Also, mFlare can be used for other light applications. Download the demo to see its awesomeness. I do not regret that I bought it.
I like it and use it quite often. Not only for Lens Flares but all kinds of light related effects. Worth mentioning: You get two licences per purchase.
There are also many tutorials on their site: http://www.motionvfx.com/mtuts,category-1.html