The best way to get a good Android phone is to get a used mid-range or high-end model from last year. Android phones built to be budget phones are awful and won't give you a proper taste of Android.
I would suggest looking around eBay and CeX (if you have one near you), look for phones like the Samsung Galaxy S2 or Galaxy Nexus, they go for £100-£150
Was thinking the same thing. A low end sub £80-100 phone (unsubsidised) is really going to give you a 'bad' android flavour.
I'd second buying a flagship secondhand from last year galaxy nexus, htc one X or S3 - yes it will cost a little more - but you'll be able to resell in a few months time without 'too' much of a hit price wise ( and probably less of a price hit than blowing £100 on a terrible low powered android POS).
I'd veer more for the galaxy nexus - simply because its 16gb and going to give you a flavour of android 4.1 / 4.2 now, and won't suck donkey balls.
Also, with rooting, is it the same as jailbreaking iOS? And how would I be able to get rid of all the company ***** and just have the 'pure' version of android?
No far from it.
Jailbreaking is required to have basic functionality that wasn't included but also offers some advanced functionality
Rooting offers advanced functionality and if you need to, you can unlock the boot loader which gives you the opportunity to install custom ROMs or even other OS'S