In your episerver.config, the siteSettings pageStartId attribute is probably set to 0. Set it to 1 (the root page). The either use PageTypeBuilder to create a start page type, or go to admin mode and create it there. Create a new page of this type under start page. It will get ID 3. Then change pageStartId to 3 and you should be good to start a VS project and start coding.

You were right, the pageStartId was set to 0, setting this to 1, gave me the root page.

But then I'm stuck again... in admin mode I can't create a start page, if I add a page, the list of page types is empty :s

I don't know how to use the PageTypeBuilder either :s

Thanks

If you have created an empty site then no page types will be available.

In admin mode you are able to create page types and associate them with page templates. Page Type Builder is a framework that simplifies this process - amother other things - by generating the page types for you.

If you're new to EPiServer then here's a great collection of links to get you started: http://www.frederikvig.com/2010/05/episerver-developer-resources/

Yeah, like I also said you need to create the page type first. But I also recommend you learn to use Page Type Builder.