Hi

best way is through web services you know OpenERP most powerfull with XML-RPC webservices

you can find many example in python site too for webservices or try

OpenERP web Connect

Thanks
Sandeep

Openlabs has developed a new connector between openerp and magento [this is not a standard addon module]. This has been written from scratch with a new design which is clean and simple. The module is also documented to explain the installation processes and the working of module.

The code is available at github.com/openlabs/magento_integration

This is written with the help of a python magento package available at pypi.python.org/pypi/magento/0.3

Other than the connector is with python scripts