Will Rooting android give me access to Google Play? If I were to get an android tablet that uses an app market like GetJar, would rooting it allow me to use the google play store? 

I want to get a Android Hipstreet Flare, but I am hesitant because it uses GetJar.
If I'm going to dive in to the android world, I want to be able to use the legit app store.
When your Android device is rooted, you should be able to flash images. There is a "gapps" package that contains the Google applications (like Gmail, ...) that is delivered with most AOSP roms, so you can flash that through recovery. 

If I'm not mistaken, this enables the Google Play Store on the given rom. I think the gapps package must be (somewhat) compatible with the rom it's being flashed on.

There are also separate apk files that you can install directly (without flashing), though I have no experience with those. And again, they probably must be compatible with the rom you're currently running.

Please refer to xda-developers.com for more information.