Hi
If you are a photoshop CS user, check out its web templates. If you are in bridge, select a bunch of your photos, go "tools", "photoshop", "web photo gallery" and then select whatever template you like.
These templates are stored in program files\Adobe\Adobe Photoshop CS2\Presets\Web Photo Gallery. What I do is having chosen a basic template I'd like to use, I copy the files for that template into a new folder under the web photo gallery presets, then manually tweak the code of the relevant files.
You can see an example of this (the site is still under construction) if you go to
http://www.didiphoto.co.uk/Birding/ and then click Accentors, Birds of Prey or Buntings. Those pages are made from Adobe Photoshop web templates. It is an incredibly simply way to design a gallery.
For a guide to using HTML check out my ancient web site:
http://www.didilogix.com/HTMLTutorial/HTMLframes.htm
I find manual tweaking by far the best method to get exactly what you want.
Best wishes and good luck!
Didi