Isley said:

Speaking about the galaxy at the end of ESB, I read somewhere that according to Leland Chee (I think it's him), what we see is actually the whole Star Wars galaxy, meaning the rebel fleet is massed outside it somehow.

What doesn't make sense with that is that we get to see a whole lot of stars in the background, yet since we're suppose to be outside of a galaxy, shouldn't there be only black void to be seen?

If you were outside a galaxy, you would still see what seem to be stars. But they would in fact be other galaxies that were far away.