Connect vertices from inner circle to outer circle I'm trying to connect the inner circle to the outer circle in order to close the mesh but I can't. I've tried to select the edges/vertices of both circles and press F 

but that doesn't seem to work, it creates two faces, one for the inner circle and another for the outer circle. 

Now I could go individually and select four vertices (two from the inner and two from the outer circle) and connect them as you normally would but that seems like a pain in the ass. I'm pretty sure there's a more efficient way of doing this, can someone tell me what's the right way of connecting the inner circle to the outer circle, in order to close the mesh? Also, why is it doing this? Shouldn't it recognize immediately that I'm trying to connect the selected circles?

Thanks in advance.
You should use the Bridge Edge Loops tool.

You can get to it three ways:


CtrlE > Bridge Edge Loops (CtrlE L) 
W > Bridge Edge Loops (W E)
From the 3D view header Mesh > Edges > Bridge Edge Loops




alternatively, AltF then AltJ, which will "Beauty" fill the the hole with triangles, then convert the tris to quads.