Hoo boy, this turned into a bit of an essay:
My personalized, really hippy-dippy recommendations for an absolutely wonderful first trip (if you want to take acid for the first time in a club, stop reading now):
Dosage: 100ug to 120ug of quality acid
Things to have list:
1. Super important: Really good, close friend who's had acid before and is an open-hearted, happy to give hugs, non-sarcastic, genuine, calm, fun person you feel absolutely comfortable with (either sober or on a low dose if experienced. I often trip-sit, and usually low dose (around 50 ug) just to get me into more or less the same mind-space) and/or, 1 friend taking the same dose as you.
2. Nature/outdoor music festival/home (see point 3) with space to roam (plus your own music + headphones)
3. Entire 24 hours set aside with NO worries about time to get home/phone parents/girlfriend/boyfriend/work or any shit like that
4. Switch off and abandon mobile phone.
5. Totally agree with "sekio" here - be really careful about herb, even if you smoke it a lot and it always 100% chills you out, take small tokes (even though acid does rather make you feeling like smoking heroic doses). If u suddenly experience mild paranoia, its likely the herb, stop smoking, you'll feel fine in 20 mins.
6. Water, food, warm clothes, cigs, lighter!!, something meaningful/special to you if you want, if you're doing a nature trip.
7. Personally, I would start off in daylight
8. Eat a decent but light meal 2 or so hours before.
9. Take your acid. Relax, try not to expect anything/force anything/fight anything.
The 5 cardinal checkpoints if you start to feel uncomfortable:
1. do you need the toilet?
2. do you need to drink something?
3. do you need to eat something?
4. are you too hot/too cold?
5. change your setting (go inside if you're outside etc).
My checkpoints:
6. If somebody/something is freaking you out, walk away
7. Talk to your friend if you need anything(that's why we're there)
8. Remember that there are no rules, if you want to roll around in the grass, do it. If you want to make weird noises, do it. If you want to cry, do it. There is no right/wrong way to trip. This is about you, and for you.
Have a wonderful journey :-D