Drupal 7, Faceted results from Search Form
Check out these tutorials for faceted / "drill-down" / filtering searching and browsing navigation without the need for solr.

http://envisioninteractive.com/drupal/drupal-7-views-with-faceted-filters-without-apachesolr/ (really good tutorial and this worked for me but for me the URLs need to be made more user friendly, not covered by this tutorial admittedly)

http://webwash.net/tutorials/intro-search-api-part-1-how-create-search-pages and http://webwash.net/tutorials/intro-search-api-part-2-faceted-search (similar to the first tutorial)

They use the Database Search module: https://drupal.org/project/search_api_db but the settings can be modified later to use SOLR for when your site hits the big time and needs the sophistication and scalability that SOLR provides. But for now, database search gets you going without needing SOLR.

For pretty URLs check out module: https://drupal.org/project/facetapi_pretty_paths - this module aims to make your URLs generated by the faceted filtering and search pretty. 

The drupal recruiter distribution is an example of using facetapi_pretty_paths : https://drupal.org/project/recruiter
- on this page you'll find more information including how to run a demo via simplytest.me with just a few clicks!

Myself I will be working out how to use facetapi_pretty_paths in my project and any steps I that work I will follow up on here (not an empty promise as I do write up my findings whenever I can)