Hi L - Princes St is shopping; Grassmarket is 'studenty'; Lothian Rd is chav street; Thistle St is 'tourists' bars;
Couple of names to look for - Cafe Royal Bar (link here to it in the Edinburgh Pubs Guide -
http://www.undiscoveredscotland.co.uk/edinburg h/pubguide/caferoyalbar.html ) is a Victorian bar with fab decoration - good as a starting point. Also 'Tiles' on St Andrews Square is OK.
Posh one (e.g for spotting THE young Princes) is in George St at Opal Lounge (downstairs from the street). Also Ricks on Frederick St. and Tigerlilly (George Street again) is more 'grown up' than some of the other options like the Three Sisters in the Grassmarket..bit stag party-ish there on occasion...
For clubs, have dig through The List mags details here:
http://www.list.co.uk/whatson/index.php and follow liknke to clubs for details.
Have fun! - oh, and come and buy some hand made crisps at the Edinburgh farmers' market on Saturday morning at Castle Terrace to start you off for the day....