This site gives you a customized breakdown of your performance with recommendations of how to improve. They work for most classes (see the chart on the front page) and specs.
- Import a log from our guild logs: https://www.warcraftlogs.com/guilds/2036
- Choose your character.
For example here's mine from normal Gul'dan tonight: http://www.checkmywow.com/reports/r9xMDq2k7yZHPfaz/71787584/23
Here's Kona's (tank) from normal Gul'dan tonight: http://www.checkmywow.com/reports/r9xMDq2k7yZHPfaz/121782849/23
You can also compare all of the fights you've participated in like this: http://www.checkmywow.com/players/71787584/bosses/1866/3?tab=basic&spec=Beastmastery
- Search for your character name.
- Choose View Reports.
- If you see: "# fights are unprocessed. Click here to process them." make sure you do so.