It requires quite a bit of patience to get up and running, the following may help you:
- Read the book "OpenERP: pour une gestion d'entreprise", or its English equivalent.
- Try any online demos you can find, or demo videos.
- Plan to have several test servers to start with (production, integration, development, 5.0 or 5.2), perhaps by using virtual machines.
- Join the mailing lists on openerp.org and launchpad, listen. Search google alot. Then think before posting :-)
- Only install the modules you really need, never install all the modules - updates will be alot less painful, and your Tterp server less fragile.
- Run on linux not windows, log to syslog or a file, but take the habit of reading the logs.
- Learn how to start Terp in debug mode. The "screen" unix tool can be handy for leaving eTiny or terp running in the background, but still attached to a console.
If you're going to program or be an OpenERP sysadmin: