It depends on how you are going to be using it, what OS, what service (web or local), what modules (CRM, Warehouse, Sales, Accounting) you must remember Odoo is huge and you cannot simply read a few pages to fully understand all of it. Documentation was fairly sparse but is improving, as is Odoo itself.
If you are developing - useful reference information can be found at https://www.odoo.com/documentation/8.0/reference/orm.html
If you are simply using on the front end, or just need tips on installations:
http://odorials.com/tutorials/general/how-to-start-using-odoo/
https://doc.odoo.com/contents/ - I believe this is V7 documentation, but should translate fairly well to V8
https://www.odoo.com/forum/how-to - Community written essays
Iw ill also follow this as I am also very new. Tnx for the question