HTML for basic webpages, static stuff etc. That should be your first thing for sure, it's fairly straight forward so you shouldn't have too much trouble. Try
http://www.lissaexplains.com it looks kiddy but it's a great site for explaining html simply and also the forums are useful.
So start with that, and you'll be well away for making webpages. Java is not to do with web, it's software stuff so forget that.
Java Script is good but I don't think it's something you need to LEARN at this stage. I've been making websites for a few years at least and I haven't actually sat down and tried to learn it yet. If you need to use any javascript you can generally find scripts or learn how to write basic functions as and when you need them fairly easily. So yeah learn a bit about how it works and what it's used for but just consider it when you need it. You don't NEED it to make webpages.
ASP and PHP - similar coding languages as far as I'm aware. They're for doing more complicated stuff. Basically server side stuff. ASP you might use for something like a simple contact form that emails the enquiry to your email address, up to database stuff, for including files. Basically when you wanna start building complex sites with dynamic content and complex functions.
JSP I'm not sure of, and DHTML I also don't know about. XHTML is just the latest version of HTML but I find it doesn't work properly in Firefox yet so I still use HTML 4.
So yeah, I don't know a lot about the complex languages, and I'm only just learning ASP right now.
So basically: HTML is the main thing that makes webpages. HTML is all you need for a great start. Oh and before I forget CSS, that goes along with HTML to make great webpages. Use html for layout, CSS for styling. You can probably stuff about CSS everywhere on the net, if you just do a search.
Worry about ASP when you need to do more complex stuff, but you'll probably get an awareness of all of it when you go along.
Hope that makes sense, if you have any more questions I'll be happy to try and help. ^^
