Thank you everyone for all your help!
I went with pre-booking just to be on the safe side; I booked at Rikka Inn on Khaosan Road. Has anyone stayed here before?
I thought it would be better to stay by Khaosan as I'd prefer to meet some other travelers, and also I believe it is near the bus station!
Again thanks for all your help! x
Khao san rd is no where near the bus station. You might be confusing it with the sort of bus area that the private buses congregate at. I don't know the Rikka, but hopefully you only booked one or two days, so if you don't like it or find something nicer in the area you can move on without too much hassle.
Sometimes if I'm coming into a place alone, I'll check out people on the plane and ask them where they are going. If you find someone going to Khao San, which you have a very good chance of, then ask if you can share a taxi with them. Saves you some cash and makes you a new friend to hang with the first few days. If you have no luck on the plane then when you come out of the airport there is a taxi stand where you get your ticket and you can ask people in the line there.