Ya it can be a little intimidating at first.
-Well basically there are some new buttons like "Apply" & "Reset". Once you allocate some points to skills, you have to click "Apply" then click on "Ok" to use the points. Till then it won't let you go lower in the hierarchy of the skill tree.
-To check skill descriptions use the "View skill info" checkbox on top. Right clicking doesn't work now.
-There are 2 buttons on top. The left one shows the whole skill tree available for your char. Hovering on a skill will also highlight in red the skills which are prerequisites for that particular skill. So hovering on Adrenaline rush, for example, will highlight Hammerfall. The right one of course closes the window!
-The skills are now divided into convenient tabs jobwise. So 1st job skills are separated from 2nd job skills.
Thats it! It's much better than what we had previously.
Cool tip: Reading long skill descriptions can be a problem sometimes, especially for skills which are always down below in the window. You can also right click on the skill icon in your hotkey bar to read description.