I have been learning the guitar for about 2 years now and i am now also interested in learning the bass alongside it. I was just wondering what the best way to go about that is. Would anyone be able to recommend any technique or theory books, or perhaps any basses that are good quality for a reasonable cheap price?

jamielowery1 I like most Bassists in the past was a failed guitarist, my knowledge of chords proved invaluable when I changed over, having owned some of the best basses (65 Jazz, Stingray V, G&L L2500, Burns 6 string Bass) I now play a Squier Affinity jazz bass V and I recommend going for a five string.
G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
I'd say it's easier to get the basics from Youtube than a theory book. Scott's bass lessons are really good imho. Maybe have a look at those.

And since you're already asking for advice I think you'll do fine. (As opposed to the guys who just play it like a guitar with fewer strings.)
Get a metronome or a drum track. One of the things that most guitarists who move to bass fail to realize is how the bass requires you to be locked in beat, and while people won't generally notice when you play a bad note, they will certainly notice when you are out of the groove.

I'll second Scott's bass lessons for videos and also recommend Hal Leonard's Bass method (get the version that has all 3 books in one). And if you can get some face time with a bass teacher or pro to break you of some of the bad habits you may bring over from guitar, its a valuable investment in time.