It's called tone and trim and requires 3 to 5 pound weights. So I'm assuming we will be using them a lot. I've done some weight lifting, but not for an hour straight with bouncing around. I'm wondering what kind I should get. I don't want to go to low, or get the 5's, and have that be to hard. *shrugs*
I used to use Firm videos back in the day and the highest weight used there was 12 lbs but I never owned 3 lb weights. I have no familiarity with a class where you provide your own weights but generally, it isn't really weight lifting, it may be called cardio weight lifting and you do a variety of different moves and your muscles generally don't reach fatigue. Also, it really depends on you. I had a friend who had difficulty doing 3 lb bicep curls. And different muscles generally have different fatigue levels like shoulders vs biceps.
If it was me, I'd probably buy the 5 lb weights and if they get to be too much, put them down during the class, do moves without them to rest then pick them back up again.
I'm surprised that you have to bring your own weights.
I use 3 lbers and 5 lbers. If you haven't used weights much, the 3lbs will probably give you a good burn at high repetitions. Especially on shoulder stuff. Sometimes I go down to 2lbs for shoulders!!
They're pretty cheap at Wal-Mart and Target, so it might not hurt to get both just in case. Have you asked the instructor??
Yes, it's bring your own weights and mat. They are done at a local HS gym. Small town.
I wanted enough that it was a challenge, but not to much that I end up hurt, you know? Seemed 3 was not enough but 5 maybe to much? Looked for 4 pound, but couldn't find any.
If the class doesn't start until December, you could start exercising at home (there is a ton of cheap DVD's around) - instead of buying weights, you can use a water bottle filled either with bottle or with sand. I don't know off the top of my head how much they weigh but that would be a good start. Based on that, you may find out that you don't need anything lower than 5 lbs and you may arrive to your first class armed with 5 and 7 lb dumbbells (instead of 3 and 5 lb ones).
I take a body plus abs class, which is a class atmosphere weight lifting session. We use 2, 5 and 7.5 pound weights with a lot of reps. For my shoulders (lateral raises and front raises) I'm not sure I'll ever be able to do more than 5 pounds. But for everything else, when not in class, I'm up to 12 and 15 pounds.
I guess my point is there is a wide, wide range. I always feel like instructors underestimate women, but I enjoy heavy lifting. 3-5 seems really light to me for anything other than shoulders. I think what I would do is purchase 3 and 5 pound weights, take a class and go from there. They're not terribly expensive and maybe you could return them if they didn't work. I like having 5, 7.5, 10 and 12 pound weights myself.
One other little trick, I like the 1-2 pound weights because they're small. If I've been using 7.5 pounds and want to increase my weight but 10 seems insurmountable, I'll hold a 1-2 pound weight along with the 7.5 pound weight which makes it an instant 8.5-9.5 pound weight. It's just a little stepping stone but it makes a huge difference.
Gonna be taking a class that involves weights
Hope its a lot of fun for you. 
