Do I have to put points into certain abilities before I can access other abilities in that skill set? For example, can I get 'bound armor' with only putting one point in unstable familiar? If not, how do I know how many points I need to spend before I can get it?

Thanks

You need to invest 1 point in a skill to use it.

Then slot the skill into the skill bar to level it up

If you do not do this the skill will NOT level up

Else...Google 'Esohead skill point calculator' and you soon know what you can do and what not.

So I can put one point into a skill line and use that skill to level up the line to 50 then i can put the 2nd point anywhere I want?