It boils down to this, what works for you... I prefer an open solution. Quite frankly, Microsoft is not known for great security (It'll get fixed on patch Tuesday!!!). Do you trust them not to have a back door? With open source, you can review the code... not everyone is a coder, but if there is a problem with an open source project, they are going to shout it out. Personally, I secure my financial data and other indicative data about me and my family that is stored on a PC... for work, I secure client data (primarily with OpenPGP, but sometimes in TrueCrypt or PGP Disk containers).
TrueCrypt has excellent documentation and an excellent forum, though it can run off topic from time to time and you get "the paranoid" type. There is another open encryption product, otfe.org... never tried it... TrueCrypt is well built and supports Linux and their are plans to support OSX. For data exchange that is appealing, but not so much to the home user. Read the online doc... or just install it and review the pdf. See if it is right for you. I don't consider myself the TrueCrypt subject matter expert, but it is useful and I do use it in some more advanced ways and don't mind giving my opinions on it here.
Encryption has a dark side too and with it being so easy to get, you wonder how much crime is contained in an encrypted message, file, volume, etc. It can be scary to think about. As a father of two girls, I don't want a child molester/sex offender using this technology, but there is nothing I can do about it expect protect my data and my kids.