I'm really pressed for time (thanks to a nightmare translation) so I don't really have time to trawl the web looking for this information, thus I turn to you guys in the hopes someone already knows =)
I'd like to add an RSS feed for the didimatic onsale page but right now have no idea of where to start. So if you know of any information about this or free programs/php scripts which can process html into RSS xml formats or sommat, that'd really help out.
Also, I could do with an RSS reader. One which allows the user to specify how often to check certain feeds (unlike the Google reader which is woefully slow).
Cheers =)

I like RSSOwl myself as a feed reader.
Server side, I don't know a lot about it sadly. You might could look into whatever WordPress or a similar Open Source project uses as their RSS engine/generator.

suggestion 1: do atom instead of rss (same thing, same software support, more clearly defined standard)
link to spec: http://www.atomenabled.org/developers/syndication/atom-format-spec.php
suggestion 2: you´re getting the info from a database anyway, right? so just take the raw data and format it as atom/rss instead of html, don´t do the feed from what the html version puts out.
I´d help more (I do have a rss/atom deal as a part of a blog/news/cms thingie I´m building from scratch), but seeing how I´m not at home and my internet surfing board of choice at the moment and approximately a month forward is my phone, I might have small problems finding an explaining code examples (not much screen real estate to get a good overview of what I´m reading or typing).
As for a feed reader, if you have a Windows Mobile touchscreen phone/PocketPC, try pRSSreader. For the desktop, the sugestion above is as good as any, I can´t remember what I used (not the same) but it slowed the computer to a crawl until I force-quit the program (might have something to do with the folder with several thousands of attached images automatically downloaded from flickr, but even before that it took a lot of power). I haven´t looked for a feed reader since, though I really want a good one.

Yeah, so I ran out of time then never really got back to this thread. As the feedcreator looks interesting for when I eventually get to look at adding RSS to the site, I've marked michaelleung as the solution.
Thanks everyone else though, if I could mark your posts as a solution too, I would.