There are quite a few online vendors for Microsoft-based training nowadays and I am sure the list is constantly growing, but here are some of the more popular online training companies I have encountered:
- Learn Now Online: http://www.learnnowonline.com/index This company used to be formerly known as AppDev and has been around for a very long time. They offer a wide variety of courses and even offer specialized developer tracks
- Skillsoft: http://www.skillsoft.com/ This company is definitely one of the most widely used online training companies by companies because of the wide variety of courses that they offer geared for developers and non-developers alike.
- PluralSight: http://www.pluralsight.com/ This company is one of the most up-to-date in regards to keeping up with the latest and greatest technologies. Many of the online training videos they offer cover technologies that have not been fully released yet and are still in CTP or Beta testing stages. However, they offer very few certification training courses for developers overall. Most of the certification courses they offer are geared towards Network and System Administrators.
- CBT Nuggets: http://www.cbtnuggets.com/ This company provides a large variety of courses and is definitely one of the most expensive amongst all of the training vendors out there. It offers some developer training courses, but is largely geared towards Network and System Administrators.
- Microsoft Virtual Academy: http://www.microsoftvirtualacademy.com/ This training is directly offered for free by Microsoft and covers most Microsoft technologies but the courses often skip over lots of material/topics needed for certification. Most of these courses are geared towards gaining a basic overview/working knowledge of a technology than gaining a proficiency sufficient to pass a certification exam.