Thanks everyone, great advice (I jave a notebook, pen and sweets already packed haha). I certainly won't be on AB tomorrow at work (!!!) but if I remember I'll try to check in and let you know how it went when I get home. They said at interview that hiring me was an easy choice... rather than that settling my nerves it's made me feel like expectations are super high! I know I can do the job, I just hope I can prove that. For now, good night. And thanks again all :-)
If it's an office job, be aware that the cliques and friendships are already in place, so be careful not to say the wrong thing to the wrong person.
Say little until you get a feel for who is your friend, and who may not be, the golden rule to remember in the first few weeks is - you have two ears and one mouth, for a reason!