I think you should be asking :

1. What would I earn as an OpenERP expert in my city?
2. What would I earn as a certified OpenERP expert in my city?
3. What do the training courses really cost (plus airfare, hotels, gifts brought home for every last one of your nieces, nephews, etc)?
4. How many months would I save by taking the courses?
5. How soon would I earn back the outlay on the courses?

If you are in a developing country those numbers don't look that great at all. However, in Japan, S. Korea, "The West", etc. it simply makes no sense to skip the courses and try to learn on your own.

On the other hand, if you want ERP for your own business, you should be thinking about core competence! Every hour you spend on stuff that's not your core competence, is money lost that would be far better spent hiring someone to apply their core competence to maximizing your leverage of your core competence. In short, don't screw around with OpenERP, hire someone who can put it to work immediately towards maximizing your profitability.

On the other, other hand -- it's a lot of fun! So then the best way to learn is to . . .

. . . solve other people's problems in this forum!

In my opinion the best way would be use it yourself. When running into issues, or having questions, use a search engine to get your answers and/or post the question on a forum (like this one).

I would say... you have to use it. Period. You need to implement it in a real enterprise and see how it works. You can read the e-books, there are many of them and they are good starting point for understanding how OpenERP works. You also need a good functional understanding, since if you don't understand accounting or material management, you are lost in any ERP, let alone OpenERP.

In case you need to learn how to develop in OpenERP, you can start by reading the Technical Memento. The developers documentation page is quite comprenhensive:

http://doc.openerp.com/trunk/developers/index.html

But at the end of the day it all comes to your experience, you need to develop or monkeypatch OpenERP modules in order to get a deep understanding of how it works. And the best documentation is, the code itself. It might not be perfect, but at the end of the day Python is quite easy to read

A great way to learn OpenERP (now Odoo) for free is to start with the official Odoo documentation and YouTube tutorials — both cover basics and advanced features in depth. You can also explore Odoo’s free online demo to practice hands-on. For deeper learning, join Odoo community forums and GitHub discussions — they’re excellent for real-world use cases and advanced configurations.

Learn OpenERP is a great platform where you can specially learn OpenERP (odoo) and its programming concepts from A to Z. The purpose of creating this blog is to help those people who wants to develop their own OpenERP Systems. Have a look please:

Odoo Development & Customization Tips

1. Install Odoo (this might be challenging for some people):

- for Windows users download exe installer from https://nightly.odoo.com/11.0/nightly/ 

- if you are using Mac you can follow this tutorial: https://www.youtube.com/watch?v=NTEga5EFSi0

- if you are using Linux this might be helpful: http://cier.tech/blog/blog-1/post/how-to-install-odoo-on-ubuntu-linux-16-04-3

2. Install some apps and configure them. You can follow the scenario like you have to deploy Odoo for a small shop (install Sales, Warehouse and all needed modules).

3. Play with it spontaneously or follow the official documentation: https://www.odoo.com/documentation/user/11.0/

4. Try to change some functionalities/looks using HTML/CSS editor, hide some fields from product form etc (in developer mode)

5. When you understand how it works then you will see some space for improvements. Start making your own apps by following official documentation: https://www.odoo.com/documentation/11.0/howtos/backend.html

6. If you can't move on/got blocked somewhere just ask for help here

Hello,

I would like to learn using ERP in the field of SCM. So, I think ebook and videos can help so much.

Tank you in advance,

Best regards

The best way to get to know OpenERP is to have a real Application Environment. Either with a customer or with your own. With a basis of concrete processes and problems you can dive into the work of OpenERP.

A basic understanding of ERP in generally is very helpful. Some you can read up through the documentation. But this is not up to date. Something you can google. Else you have to ask either here in the Help section. The source code is still the most accurate and best way to find out how something work. Of course you need a basic understanding of the architecture of OpenERP.

Start by learning Python, simply Python without any frameworks. Video tutorials is probably the best way to learn but you should totally do everything you see in the video just to make sure it leaves a print in your memory. Don't forget that practicing is the most critical point here. Also, choose a few tech blogs and read them. Here's an interview with an Odoo developer with over 10 years, you should totally check it out:
https://mobilunity.com/blog/interview-with-a-dedicated-odoo-developer/