Please can someone point me ion the right direction?

i have to setup a listx which displays some events
e.g.

titel date category

so far no problem :-)
now i want to let the user filter those results within one module. should normally no problem, but requirements are:
1. should be seo friendly (not using ajax?)
2. user shouzld be able to filter by date, category, date and category

how should i start this filtering process.

thanks marc