One Look Is Worth A Thousand Words
For anyone to experience Odoo (both frontend e.g. shop, blogs, forums etc. and backend ERP systems like accounting, inventory, sales etc.) personally, visit http://runbot.odoo.com/runbot
I normally go with Odoo/enterprise lastest version, click the blue run button,using admin as both account name and password. voilà, you are inside Odoo.
You can now explore every details of Odoo yourself. Checking the features provided inside each application e.g. Accounting App, Inventory Management App etc., how they work with each other. Change settings to achieve more advanced functions in Odoo for your specific needs. Install more apps from Odoo Apps to seamlessly integrate all your business flow.
Understand how Odoo handles different applications inside ERP system
Odoo itself provides really good and interactive documentation for us to understands each application that can be used in ERP system. Accounting, CRM, Sales, Purchase, Inventory etc. are commonly needed for any business. To know the terms used in Odoo ERP and how you can customize everything for your business, Odoo official user doc is definitely a must read.
If you prefer watching videos, Odoo has official channel and here is the link to Odoo App Tour
To learn and understand specifics of each application inside Odoo ERP, you can follow the official Live Webinars , they regularly update and introduce how to configure things for latest version, the guys who present it always deliver a great tutorial, it is a good way to keep yourself updated to the Odoo knowledge and skills.
When you have questions
You can always go to Odoo community to post your questions, there are so many active experts there, and your questions will be very fast answered.
Discover more by reading the developer documentation
For people who wishes to level up, it never hurts to read more about developer documentation, from there you have a clearer understanding how Odoo architect and structure itself and you can know better how to exploit Odoo to serve all your requirements.
Google and Bloopark
Google is almost always our best friend, you can try all your Odoo related questions there, also in Bloopark, my colleagues wrote various clear and helpful articles to introduce Odoo features, customization, evolvement and comparison of Odoo version. If I missed any other resources to help beginners quickly get on with Odoo, please do let me know. Thanks :-)