here is something i recently discovered. i haven't tested it yet, as it is not compatible with the scripting tool i'm using currently, but looks interesting:
zen coding -it's like a shorthand for HTML/CSS... i.e., you type just a few characters and out pop a fully indented properly structured code. plugins currently exist for programs such as Notepad++, among others.
i agree with the others, you need to check out
w3c schools and also the
w3c standards documentation.
I learn a lot from the "SAMS Teach yourself HTML in 21 days" book, though admittedly this was some time ago (before XML, flash etc started infusing the web) - i think the newest edition is 'webpublishing with html and xml', or something. they also have editions such as 'css in 10 minutes'... they're worth checking out.
other points to consider are accessibility - while there might not be too many blind people accessing YOUR website, these guides actually make you think and use HTML and CSS in a much more
appropriate and
elegant way.
many countries also have laws regarding accessibility for commercial websites. there is much
accessible help on the web for accessibility.
If you're big on design (you mentioned two image manipulation programs) then you may enjoy the artistic flexibility that
flash can offer, though keep in mind accessibility is harder to implement in flash than it is in html. though nothing beats the elegance and simplicity of a well-scripted, crisp and clean html/css site.
you also have to keep in mind
different compliance of BROWSERS to scripting standards, and that your code may look different in IE to FF to Opera to Safari to Google Chrome, etc... the trick is to make them look as alike, yet still pretty and functional. this is where flash may have an advantage.