Alcohol is not allowed in Libya. The best things to drink are:
Coffee, although they do seem to want to give you Nescafe, as they think it's pretty cool; but just about everywhere you can get cappuccino or Arabian coffee, which are pretty good.
The mango juice is good and very thick.
Coke, Lilt, and 7Up cans are popular, as well as the lemon and mint teas.
Alcohol-free beer is widely available Becks, as is 'Spitz', which tastes like campari or cough mixture. If you really want alcohol, wine is available from butcher's shops, but it's expensive whisky is about USD 100 per bottle. It is said that the penalty for being caught drunk or with alcohol is to be driven back to your hotel room by the police. While this sounds safer than riding the local taxis, such approach is not recommended.
smoking
A smoker's paradise. You can smoke anywhere you like. The "no smoking" signs in airports appear to be a guidance note rather than a command.
Hand-rolling tobacco is not available, but normal cigarettes are widely available and quite cheap, although slightly different than their western counterparts.
Duty free is somewhat limited, so it is best to buy on the way out rather than on the return journey; this obviously, does not apply to alcohol.