Some web sites, like google, work very well on the Pocket PC and the Palm machines. Others, like my feeble attempt, do not do so well. Does anybody have guidlines on how to make a web site be PDA compatible? I'm not using any fancy tools, I use the Notepad text editor to write simple HTML.

The really simple answers:
0) Start with the page templates at http://www.mobi/ (developers area). In particular make sure that you keep the correct XHTML MOBILE declaration line at the top of every page you generate.
1) Test your site on the simulators at http://www.mobi/
2) Test your pages using the ctl-alt-V built in validator in Opera: it will use the declaration line from (0) to get your page validated correctly at w3.org, even pages that are not up yet.
3) View your pages using the "small screen" mode of Opera. Also test in FF, which handles XHTML. IE6 doesn't (usually) in my experience.
4) Use a real mobile phone.