How do I figure out what weight of dumbells I should use?

I'm just starting out an exercise routine with dumbbells, but don't know which size to use.How do I figure out what weight of dumbells I should use?
Start with 3 lbs for each side... work up to 5 lbs., then 8, then 10, 12, 15, etc... Three pounds might not seem like a lot, but if you are just starting out, your muscles need to become accustomed to lifting. Muscles tear and rebuild (that's how muscle is built and toned) so you don't want to start with weights that are too heavy... you could do more damage than you realize... and be in pain for several days! The first couple of reps might not seem like it's doing anything, but you should feel your muscles contracting after about 8 or 10 reps. If this still isn't doing much, you are ready to move up a couple of pounds. Good luck! And keep at it... long term results don't happen overnight but are the most rewarding! :)How do I figure out what weight of dumbells I should use?
Start with three pounders and increase the weights gradually to whatever you can comfortably use for three sets of 10 reps per set. Arnold Schwarzenegger wrote a great book on weightlifting for women. I highly recommend his books, for safe and effective exercise.
Start with the lightest weight you can comfortably do, say, 10 reps with of whatever your chosen exercise, provided you can still ';feel the burn.'; When it gets to the point where you can do 25 or so reps easily, without being able to feel it working your muscles, then move up to the next weight.
start with five pounds and see how that feels. You should be able to do 12 to 15 reps and three sets. If there is soreness and fatigue that is good, if not up it a pound until its hard to finish the last set.
It all depends on tall the guy is.