I have a list of websites that i often search to find solutions or news about Fortinet.
Below is the link list, with some description:

1. www.ipspace.eu -> Yea, i often use this if i forget some troubleshooting commands
2. kb.fortinet.com -> A lot of good articles related to Fortigate problems
3. docs.fortinet.com -> A list with all the FREE books Fortinet provides for its different appliances
4. emea.fortinet.net/fortinet/troubleShooting.php -> used for Hardware Troubleshooting
5. url.fortinet.net/rate/submit.php -> If you found an URL that is put in a wrong category, here you can request a fix
6. campus.training.fortinet.com -> here you can find a lot of useful and FREE Fortigate webinars

That is it.

Hope you enjoy them.