That first link should always be up to date (as should the second), and it is as of right now. There is also the Wiki's installation page you could look at:
http://wiki.gungame.net/pages/InstallationThat error (Invalid access to memory location) occurs sometimes for me as well. I have yet to figure out why that happens and how to eliminate that issue. For now, the way I get around it is if Steam is loaded, exit it and then boot the server. If Steam isn't loaded, load it and then boot the server. Sometimes going into CS:S (or exiting from it if you are already in it) eliminates the error. Basically, trying to do something to cause the memory to change, and then start the server.
I will try to sort this out, but I'm not sure how easy it will be to eliminate this issue completely.
Satoon