Replying to Flying with skis

Flying out to Utah tomorrow and had a couple questions because this is my first time flying with skis.  I'll be flying on Southwest.

First, will I be charged extra for putting two pairs of skis into one ski bag?

Second, I will be taking my boots as my personal item; this is recommended, correct?

Lastly, I was just wondering if there's anything you guys think I should know since I've never done this before.