When I use it, I usually take 500mcg/day for the first 10 days. Then after that, I will take 500mcg pins once or twice a week (depending on how much I'm needing to maintain my tan). I usually pin approx. 1 hour before hitting the sun/tanning bed - if possible.
As for length of tanning, I can't really say much as far as tanning beds - because they all seem to differ. As for the sun, an hour or so is usually good for me to see a noticeable difference. If I spend the day at the beach (even during my maintenance stage) I will be dark dark brown the next day. BTW, thats with using 45 SPF - 60 SPF sunblock.
Just remember, you'll probably have to tweek out your own best method, as everybody's skin/melanin levels are different.