Not sure what it is I should buy?

Hi, I am new to Roll20 and leading my first campaign through Strahd! (Loving it!)  I am trying to understand how to best fill out the missing content for me and my players. It would seem i need to purchase the Players Handbook and then i could share that with them. Is that how it works? Then the all access sub. Is that different? Do I need it too? Can I only buy the sub and not the handbook? Thanks!

So to start to answer myself. Looks like I can buy just the book, and then be able to share that with just 1 game. Then if I go PLUS thats 3 games, then PRO for 5. So what I really need to know is, if you go PLUS or PRO, will it include the handbook? 

I think you need a plus or a pro account to share any of your books beyond one game.  I have the PHB and Monster manual and the PHB can be accessed by all my players, its very handy makes life a lot easier for all. Without a PHB its just the basic free DnD rules. I did manage a year doing OOTA with only a plus account but it does create a lot more work for the DM.

It has been done, thank you :D