I have about 7 Javascript files now (thanks to various jQuery plugins) and 4-5 CSS files. I'm curious as to what's the best practice for dealing with these including where in the document they should be loaded? YSlow tells me that Javascript files should be--where possible--included at the end. The end of the body? It mentions that the delimeter seems to be whether they write content. All my Javascript files are functions and jQuery code (all done when ready()) so that should be OK.

So should I include one CSS and one Javascript file and have those include the rest? Should I concatenate all my files into one? Should I put Javascript my tags at the very end of my document?

Edit: FWIW yes this is PHP.