On Windows, I use Notepad++ for my HTML editor, but I'm having problems finding the same thing in Linux. Basically, I need a lightweight editor with HTML highlighting, that doesn't require getting used to a lot of new commands.

Tea for Linux?, http://tea-editor.sourceforge.net/

also http://freshmeat.net/ has a great repository with a good search function you may find useful...

P.S. KDE also uncludes Quanta Plus you may find interesting, and Kate & kwrite are great text editors with syntax highlighting supporting many languages including css, html & javascript...

I fought vi when I first had a c programming class that forced us to use Vi.
That was years ago.
Now I love vi. Yes, you would have to learn a whole new way of editing, but if you are going to be using Linux vi is normally loaded by default on all distro's.
Vi has two modes. Command mode, and insert mode. In command mode where when I hit i it equals "go to insert mode".
Hitting the esc key takes you back to command mode. The general idea of vi is that your fingers never have to leave the keyboard, since you can do all funtions with different key combinations.
In command mode j = go down one line
k = go up one line
shift ZZ = save and exit
/ bozo = find bozo in the text
n = find next
. = repeat last command

I've not scratched the surface but hopefully got you interested. Vi is So worth the effort you'll expend to learn it, course that is JMHO.

And usually on modern distros with xterms, the normal arrow/cursor keys work as well and are more intuitive
In fact, just FYI, you'll often find that the vi cmd is actually symlinked to vim (vi Improved).

If you use KDE ... try Kate.