Well I want to thank everyone for all there help. This is my first armor model and I do have to say its turning out way better than I could expect. My question is Im getting ready to drybrush and wanted to know what is the best kind of brush (size and type)to use would be and is there any thing special you have to with the paint (thin it down)?

Can't give you a number, but you'll want to use a soft, flat and relatively wide brush. If you have some old paint that has lost some of its solvent, that would be best.
Just touch your brush to the paint in the cap after you've shaken the bottle. Then wipe just about all the paint off on to a rag. Drag very, very lightly. Repeat until it looks like you need a couple more passes and stop before you do those two more passes.

Majorbeefalo, (love the name) if you can get hold of some artist tube paints, I would suggest that you use these. Enamels and acrylics tend to dry out quickly and can result in a clumpy (is that a word? :-) ) finish. The oils do take longer to dry, but go on extremely smooth. They also offer the advantage of being easy to clean up should you goof something. Simply wipe it off and start over. They can also be mixed with enamels as well. With the oils there is no need to thin the paint as it is sufficiently thin right out of the tube. Practice on some obscure part of the kit, like the bottom of the hull, or even a trashed kit you may have to get the feel for them. I think once you try them you will like them....alot. Last but not least, welcome to the BIG-A!! Lots of knowledge and advice to be found on this site. Its a great place. Enjoy. "Q"

It is my experience that oils. enamels and acrylic can all be use in drybrushing because each has different qualities. For example acrylics dry quickly so a very subtile effect can be achieved with a few thin passes. Enamels I like to use for bright scratched metal using metalics. Oils are good for highlighting and stains. Try experimenting on an old model and see the effects that can be achieved with all the mediums.

One note with oils, let a dab sit on a piece of cardboard for 10 minutes before using it. This will pull out any extra linseed oil, and allow it to dry faster, and have less sheen.

HTH