I think if you are going to be doing ANY type of drug, it's always a good idea to have Benzo's on hand...just in case.
They can help calm someone who is having a bad LSD or 'shroom trip.
Can't go to sleep from all the coke or crystal you've done? Take a benzo or two.
Your overcontrolling girlfriend won't stop bitching about...well...everything? Take some Xanax.
They each have their own pro's and con's. Though I don't really like the comparison, "Drunk" is about the best way to describe it, yet it's still a misnomer.
Expect relaxation, mild to moderate euphoria, drop of anxiety level, 'sillyness', the 'wild & crazy' attitude that you may get from alcohol, and eventually sleep.
Snorting them really is a waste. Just take them orally...that's what they were designed for.
For your first time, and perhaps anytime after that, do *not* drive on benzo's. I have first hand experience on this, and it has lead to more than one totaled car.
Mixing with alcohol? Some like it...you will definitely feel the effects of both drugs much faster...but you will probably black out and not remember anything in the morning. Perfect for a fratboy party.
Mixing with alcohol and driving? Never. Period.
They mix well with opiates. I don't reccomend mixing them with Meth or Coke to get high...only take them on the comedown.
I think they go great with acid personally, but many disagree.
Don't overdo it your first time, as you have no tolerance and they will probably hit you like a ton of bricks.
I'll give my reccomended recreational virgin dosage for the most common:
Xanax: 1 mg
Valium: 20mg
Klonopin: 2mg
Overdose is not really a concern, as it's very unlikely. However if a friend of yours does happen to take a LOT, expect him/her to sleep for many many hours, perhaps days.