luvrmoney
Most dolls that retain value are porcelain for starters. Next would be maker Madam Alexander and .Effenbee. Look under dolls hair in back.See if there is a number or any mark on dolls neck.

snowgirl
Go to ebay.com

cltd
www.dollreference.com is my favorite site for identifying dolls and ebay is my favorite price guide. I'm assuming that the dolls you have are not marked in any way? If not, it's best to search under the material they are made of. You can generally date a doll by what it's made of... china 1800's, bisque late 1800's - early 1900's, composition 1920's - 1940's, hard plastic late 1940's - early 1950's, vinyl early 1950's - present, porcelain 1970's - present. Most modern porcelain dolls do not have a high resale value, unless they are made by a doll artist with a following. Those dolls are usually clearly marked. Many vintage play dolls from the 50's and 60's are very collectable as are most earlier dolls. If you need further help you can email me through yahoo. I've been collecting dolls for about 40 years and can probably help steer you in the right direction (especially if you have a picture)