Ceud mille failte to Scotland and congratulations on choosing Edinburgh; you'll have a great time here. Drop me a line if there's anything I can do for you when you arrive. (There's quite a few FTers based here or with extensive knowledge of the city, so you're in good company).
The food isn't so good at Gringo Bill's these days...not least because it closed more than a year ago.

It has been replaced by the Tijuana Yacht Club (110 Hanover Street, 0131 220 1208) but the new place has an even better reputation for great Mexican food with a little humour. It's been a while since I was there; we did pitch for a meal there during an EDI do last year, but
SanDiego1K made it clear that she hadn't travelled 5,500 miles from Southern California just to visit a Mexican restaurant

And who was I to disagree, especially since she had schlepped several kilos worth of margarita mix over with her as a gift for me?

A little closer to the university area,
Pancho Villas also does good food and has lots of student specials if you're on a budget. Further away, in affluent Stockbridge, The Blue Parrot Cantina (49 St Stephen Street 0131 225 2941) gets some good reviews, mainly for its excellent drinks. I think the Haw House has also closed, but I could be wrong.
What are you here to study? I take it you have seen the
Edinburgh info thread? Best post any further questions there.
Oh, and don't worry about trying to predict the weather. You can't
Alastair