Ok, I have a complete single armature (face and body armature) and a single model(body+head), here are the screenshots, should I separe the face bones from the body bones? I was adviced to use shape keys to animate face, but I believe this can´t be made in a game, I´m wrong? Should I separate eyes from the body model? Please help me solve this gaming question
Eyes you probably should have seperate, you may want to consider modeling the eyes from scratch for this model. Look at http://www.blendernation.com/2006/04/25/orange-dvd-production-started-free-downloadable-model/ and http://www.blendernation.com/2006/04/10/free-rigged-model-ludwig/ for some examples.
This thread might be of interest.
http://blenderartists.org/forum/showthread.php?t=70892&highlight=mouth+rig+armature
Thanks Bugman_2000, I think I´m in the right way, and cowdude, I will download the models, It´s funny how these free models boosted my modelling,mapping and animation at an incredible level, when I was beggining in blender,(super Wu man game models, only for learning purposes)I think more newbies should see these examples too 
, one more thing:
Someone know how to export an animation to an video file (so I can send to my friends) , or film the screen for a determinate time (with the same purposes)?
In the render settings, Format panel, there’s a selection box that probably says “jpeg”.(next to the crop button) Click on it and you get a bunch of selections, one is AVI Codec. Select that, then a Codec selection dialog pops up. Pick whichever codec you and your friends have, then the Anim button will produce a video file instead of a series of stills.
[EDIT] Oh yes, the name of the file will be something like 0001_0360.avi for an animation from frame 1 to 360.
Why when I press control+render this window the resulting animation is quick and textured, and when I click anim the resulting animation appears only to be shaded, and take too long to load (and it is without textures) ,why?