Sorry, I don't think they are a good reference at all.
Take this, on W3Schools:
http://www.w3schools.com/html/html_forms.asp
1. Bad initial description "HTML Forms are used to select different kinds of user input."
2. No notes on labels
3. Trivial input type descriptions
4. No description of form methods
5. Example forms use GET instead of POST, without mentioning POST's and when GET and POST should be used.
6. HTML5 form elements and attributes thrown into additional sections that are to be frank, not that useful.
Now compare that to this:
http://reference.sitepoint.com/html/elements-form
While not perfect, it groups forms together as one thing; with a decent description.
The main areas of interest are clear, selecting "form" takes you to a detailed description of the form element, the references to other form elements and attributes are linked.
The description of each element, how they work, their compatibility and so on are clearly described, the examples useful and in context and they support user contributed notes.
Overall, it's a strong reference; when backed up by their other materials such as books and tutorials, it's an all in one reference that is really useful.
W3Schools is basically useless.
Thats the problem with the classroom, it's very difficult for the person teaching to stay up to date, so out of date stuff gets taught.
It's debateable whether ASP is that useful to teach as a first language without specific reason, PHP is much more widely used and as a language is probably more useful. Also due to the nature of the language it's easier to pick up.
Other than that, I agree with your comments.
