The Microsoft Technology Associate, or MTA, credential has been around since July 2010, but until a few weeks ago, was only available to cert candidate who participate in some Microsoft IT Academy program -- mostly in high schools and colleges. Now MTA exams and credentials are available to any and all interested parties, both inside and outside academia.
The home page for the MTA program describes it as "a recommended entry point into IT certification and job preparation," designed to "validate your core knowledge." The program is divided up into three silos:
Here's a nice graphic that helps to organize all these items (to see how they map into MS certs overall, download this MTA Certification Path graphic [PDF]):
Here's how the MTA certs map out
You can already find plenty of materials on the various MTA exams right here on the PearsonITCertification site by searching on individual exam numbers (for example 98-349 for the Windows Operating System Fundamentals). Expect to see Exam Crams and Cert Guides popping up right here in the near future, too!