COMPANIES I USE AND RECOMMEND
For DNA Testing:23andMe.com
For autosomal DNA testing, start with 23andMe ($99) and then transfer your data to Family Tree DNA's Family Finder ($89). That way you can affordably be in two atDNA databases.
Family Tree DNA
*Mitochondrial DNA (mtDNA) testing is usually not genealogically informative, so I recommend that women, instead, start with autosomal DNA testing and men test either their Y-DNA or autosomal DNA (or both).
For Genealogy Research: