Texuture Size to Game Size

Hello all, I've been away from SL for a good year and a half now, because my dial up made it unbearable. Am on DSL now and its glorius for SL, and am working on a few costumes in my spare time. Now, Texture mapping has me a bit befuddled. I know there are templates for the clothes and bodies for SL, and having a good amount of experience with Poser, those are no problem for me. The problem for me is texturing prims. How does one figure out the pixel size required for any given prim in SL? I created a leaflet of paper using the box prim, and when I placed my texture map with its text onto it, the text is waaaay off the prim. As an aside, how does one edit only a particular face of a prim? I have heard this is possible, but never found out how to.

Thanks in advance

-Furry Artist/Builder, Allabaster Gupte

If your texture is a seamless one then you can mess with the repeats on the prim "texture" tab till it looks right. If it is a single texture (say the side of a buiding with windows and such) then you need to keep in mind that aspect ratios will change with the size of the prim.