'Guides' was an upload category in F1 2013.
When the categories were expanded from the few in the F1 2012 modding forum, this category was created for uploadable guides i.e documents like pdf files etc.
This category was removed, but AFAIK the Prefix for an upload was left behind (so it seems). By prefix I mean 'Skins'. 'Misc' thing like that. If you look in the F1 2013 download section, you can see that the 'Guides' category has gone. It wasn't used.
http://www.racedepartment.com/forum/resources/categories/f1-2013.68/
Creating a post in the modding forum and giving the prefix 'Guides' is much the same as someone creating a thread with the prefix 'Skins', then asking a question about skins in that thread.
As you know, no threads can be created in the F1 2013 mod forum, unless it is an actual mod release, no other threads are allowed there.
Your video (which can be added to the Video library for F1 2013), is a specific guide for modders. So the logical place for it, barring the forum rule mentioned above, is the modding questions sticky. A place where most people go to get info about modding.
There you have it ......
Cheers
Graham