I would do it like this, even in this order:
HTML (not XHTML, it's just for more integration to XML but it's not like we need it, SGML is going to be the next HTML I think, w3 says so)
CSS (good addition to HTML. It'll help you style your site up)
JavaScript (Good intro to PHP, very similar syntax. On top of that very helpful, active scripting is fun!)
PHP (Preferred over perl, easiest to learn IMO of the web programming languages [not scripting languages like html and css and js])

Then I would try to go with like Java for more advanced programming for the web.