Is AES restricted to only 64 characters for the key/password? I am wondering if AES only supports 64 character passwords?

When using truecrypt, the maximum character limit on passwords is 64 characters; however, when using WinRAR, the limit is 128 characters.

What determines the length of passwords I can use with AES?
Key sizes for AES are 128-bit, 192-bit and 256-bit. Depending on how you pack characters into bits, will determine how many characters that makes up. For example, you could pack 1000 characters into a 128-bit encryption key using something like PBKDF2 or scrypt.

That said, I wasn't aware that Truecrypt only supports 64 character passwords. Assuming that is correct (and I have no reason to doubt you yet), you could always use a keyfile with Truecrypt if you need a longer password, but keep in mind that a randomly chosen, 64 character password is surely infeasible to break any time soon.