Way to import a rig for my character?

Say I have a prepared rig here

How can I actually import the rig into my own blend. file to use it for my character?

If you want to import it into an existing blend, go to ‘File > Append > Browse for the rig > Object > Select everything and press Done’.
I’m no expert in Blender, but from what I know, there could be possible texture glitches. If the above doesn’t work, then I’m pretty sure there’s other ways to do it?

With Append (File > Append).

Append will show the other blend file containing the rig as a folder structure, where you can browse to the object and then the rig. You could even append actions if the rig has any.

I generally keep my rigs in one place on my computer and link them in you then have to make your rig proxy. So one rig is shared across multiple files and editing one file updates the others e.g. If you want to change textures or remodel the character etc.

Nathan Vegdahl’s humane rigging has a whole chapter about preparing your rig for linking(I think humane rigging is now available on YouTube if you don’t have the DVD).

Seeing as he was one of the co-creators of the Cookie Flex Rig I am sure it is already set up for linking. Linking not appending seems to be the preferred method of using rigs especially for you are animating for shorts films.

Linking is the best method. Just as Tyrant monkey said. It allows you to have a set and animation file. The set file is linked into your animation file. This allows you to split up mesh building, light setups, and setting up that mesh. Also good to have a rig file within your production file so you know where your rigs are.

Basic things to further learn.
Folder structure for your animation
Set builds

Just for fun I would suggest learning what rule of thirds is in photography. Its a basic that will help you down the line :).