how many reps and how many sets?

I'm just started strength training at home, by myself. I use resistance bands.
How many reps and sets should I be doing?
I have read 12-15 reps and 3 sets, but I've also read 5-8 reps and 3 sets.

Here is a post I made to another member that asked a similar question. You can get a 40lb set of Cap adustable dumbbells at walmart for $30.00 and add additional plates as needed for $2-4 dollars each.

Ok here is the program/split. To keep it simple try to do 8 reps for every set. If you can do 10 reps, raise the weight for the next set, if you can only do 7 reps or less ,lower the weight for your next set. Also try to limit your rest periods between sets to between 1 minute and 1 minute and 30 seconds. I choose to do my cardio and abs on my off days but you can mix them in to fit your schedule/ needs etc. Also please dont be intimidated by lifting!! (we all were when we started but quickly realized that there wasnt anything to be scared of)

Monday: Legs-
Squats x 3 sets. http://www.exrx.net/WeightExercises/Quadriceps/DBSquat.html
Lunges x 3 sets. http://www.bodybuilding.com/exercises/detail/view/name/dumbbell-lunges
Step ups x 3 sets. http://www.muscleandstrength.com/exercises/dumbbell-step-up.html

Calves-
Seated Calf Raises x 3 sets. http://www.muscleandstrength.com/exercises/seated-dumbbell-calf-raise.html
Front Raises x 3 sets. http://weighttraining.about.com/od/exercisegallery/tp/frontdumbbell.htm

Tuesday: Back-
Pull Ups x 3 sets ( use a chair and push off it with one foot to assist you as much as needed to complete each rep.)
Dumbbell Rows x3 sets. http://www.bodybuilding.com/exercises/detail/view/name/one-arm-dumbbell-row
Bent Over Rows x 3 sets. http://www.bodybuilding.com/exercises/detail/view/name/bent-over-two-dumbbell-row

Biceps-
Curls x 3 sets. http://www.bodybuilding.com/exercises/detail/view/name/dumbbell-bicep-curl
Concentration Curls x 3 sets. http://www.muscleandstrength.com/exercises/concentration-cur.html

Thursday: Chest-
Bench press x 3 sets. (use your bar)
Incline pushups x 3 sets ( use the bottom step of any set of stairs and do as many as possible for each set)
Dumbbell Flys x 3 sets. http://www.bodybuilding.com/exercises/detail/view/name/dumbbell-flyes

Triceps-
Extensions x 3 sets. http://www.muscleandstrength.com/exercises/one-arm-seated-dumbbell-extension.html
Kickbacks x 3 sets. http://www.bodybuilding.com/exercises/detail/view/name/tricep-dumbbell-kickback

Saturday: Shoulders-
Shoulder Presses x 3 sets. http://www.bodybuilding.com/exercises/detail/view/name/dumbbell-shoulder-press
Front Raises x 3 sets. http://weighttraining.about.com/od/exercisegallery/tp/frontdumbbell.htm
Lateral Raises x 3 sets http://weighttraining.about.com/od/exercisegallery/tp/frontdumbbell.htm

Traps-
Shrugs or Seated Shrugs x 3 sets. http://www.bodybuilding.com/exercises/detail/view/name/dumbbell-shrug

Lower Back / Glutes- ( Yes its leg exercise but you dont want to do deadlifts and squats on the same day)
Dead Lifts x 3 sets. http://www.bodybuilding.com/exercises/detail/view/name/stiff-legged-dumbbell-deadlift

Buying dumbbells was the best thing I've ever done. I've been doing a full body workout 3 days a week for a month now and am definitely reaping the rewards.

Squats, Deadlifts, Overhead Press, Bench Press, One Armed Row, Bicep Curls, Tricep Extensions 3x10 followed by an ab workout (I do as many crunches as I can followed by planking for as long as I can repeatedly).

There is a lot of conflicting information to be found about strength training on the internet. It took me weeks to sort through everything then decide what would be best for me. The most important thing is finding a program that suits you and sticking with it.

I based my workout around this article: http://exercise.about.com/cs/exerciseworkouts/a/weight101.htm