Well the first objective is to be at least a "Council" member in a coven, you can do that in two ways;
Join a coven and work your way up to that position.
Or, join Spell Casters and instantly be accepted in "Council".
Spell Casters is were most of the beginners go to because they can post fake spells or instantly be able to post spells and articles in general without the hassle of fighting to prove your worth. Now, how to post the spell once you are a "Council" member, you can go to the Spells section of the site and on the right-hand conor under the "Mail" and "Sign-out" button there should be an "Add Spell" tab, click it, and there you go.