TFS is a beast, but it provides us with many wonderful tools. I've been a TFS administrator for the last six years and I wouldn't trade it for any other tool, but that is my opinion. :)
If you are truly new to it, my suggestion is to start checking out a few books. An author I recommend is Brian A. Randell (make sure you use the middle initial or you get a different Brian Randell). He has co-authored several books on TFS and is a Microsoft MVP in the ALM field. I met him at a conference last year and the man knows this product inside out. Look up his books at your favorite books store.
If you aren't into reading books, there is a free site that Microsoft provides which is great for learning their technologies. Take a look at
Microsoft Virtual Academy[
^], they have a lot of courses on TFS. Some of them are for 2012 and some are for 2013. While a lot changed between 2012 and 2013, a most of the core concepts stayed the same.
Hope this helps!