Q:

How do I adjust the FOV for Skyrim? 

The default FOV is rather low and annoying, I would like to increase the viewing angle up to something like 100, how do I do so? 

A:

Go to your My Documents -> My Games -> Skyrim -> skyrim
Create a backup of the skyrim.ini file in case you need to change back later. 
Open the file, then scroll down to where it says [General] (for me it was at the top of the file). 
At the bottom of this section, add fdefaultfov=XX (where XX is the FOV value you want to change to), in your case it sounds like you want it to be 100. 
Save, exit, and play!