I am not sure which books  you have already purchased, but here is a list
of more books that may be helpful:
http://heathersolomon.com/blog/articles/148.aspx#RecRead" target="_blank" rel="nofollow">heathersolomon.com/blog/articles/148.aspx#RecRead

It sounds like you are going in the right direction, portals are meant
to be a launch pad to other information, to act as a portal  in the true
sense of the word. Static information  geared towards a large audience
is better suited for a portal, while more intimate team information is
better suited on a Windows SharePoint Services (WSS) site, also referred
to as team sites  off a portal. WSS sites are for team collaboration,
more secured list and file management  and for short term content,
meetings and projects.

SharePoint is a product where the best guide is to learn by doing. I
would suggest you set up a test portal and WSS site so you can use it as
a playground to get familiar with SharePoint. I also have a large list
of resources available that may be helpful:
http://heathersolomon.com/blog/articles/148.aspx

And newsgroups like this and blogs will provide a lot of information.

As for the document  and image  management, do your homework on that first
as many people get frustrated with the document and image libraries
within SharePoint. They were not built for heavy file management. You
may be better off investigating a document repository tool for that.