I have black hair and I was wondering how would I get it light brown or blonde? What kind of product would I use?

Black hair is the most difficult to lighten. A very strong product must be used. Because the hair is so dark it will go through an orange stage during the process and this is a tough stage to get through. First the hair must be strong and in good shape. Then a cream bleach product for on the scalp must be chosen such as Clairol Compliments Gel Lightener or Wella Speedlight. An all over bleaching is not my first choice, I suggest a "Frost" or a "Weave" to reduce the amount of damage. Also, a "Weave" or "Frost" only needs to be redone every 4-8 weeks. An over all bleach will show dark roots in 2 weeks! 

Frosting kits usually come with everything you need. I also think a professional is the best person to do a frost or a bleach. At home, frosts are chancy. Strands of hair are pulled through a frosting cap. Usually, lots of holes with small strands of hair through them make the prettiest weaves, but some prefer large chunks of hair pulled through. Hair is pulled through the cap with a crochet hook. This process is very uncomfortable on long hair. 

Frosting bleach is applied over the cap to the exposed hair, and a plastic "shower" cap is placed over the hair, bleach and frosting cap. Process about 40 minutes. Don't remove the cap until you like the color of the hair that has been bleached. Shampoo the bleach off. If it is an ugly orange color, the hair needs to be completely dried (Don't take the frosting cap off!)and the bleach remixed and reapplied. Hair will not take any more than 2 bleachings so hopefully the hair will lighten enough on the second bleaching. Do not leave the bleach on any longer than necessary on the second bleaching. Get a really good conditioner (like Redken Extreme Pak.)