Merging separate files?

Ok, I’m sorta new to Blender (using blender 2.5)
I want to know if theres any way I could merge several separate Blender files.
I’m creating a game in Unity Indie, I have no money for Pro which is needed in order to use asset bundles, which, unfortunately, are needed to make create a character sections. Unless you know how to code around it.
So I need to create every single possible combination of clothing items and code them all in D:
I figured this would be easier if i made, for example, several different upper torso files (t-shirt and arms- so it would be the same model but slightly edited and retextured in each file) leg files (collection of skirts and trousers) and head files (hair). So in order to create these custom characters, I wanted to be able to open a head file, a torso file, and a leg file, merge them, save it, and make another combination, so I wouldnt have to re model and re texture every single time!!
I dont know how to merge separate blender creations though, this is a problem as each and every single piece is in a separate file!! :spin:
So is there any way I could do this? Bring together totally separate files and put them together?

Append objects/materials etc from one blend to another with Shift+F1

Ah! Thanks so much! Its all so simple now >.<
Forgive me, I’m pretty much a n00b, I know the basics but not much else