With a non-trivial web site, the more browsers you test, the more cash you burn through, and (if you're not very careful) the more twisty the web site HTML and CSS code gets. But you already know that.<p>Verify compliance with W3C standards as a baseline, follow a proper subset of those standards whenever you can, and then point-test with large footprint (and buggy) browsers you might have to deal with. IE, for instance, can need special coding. FF, Opera, Safari and other such do not generally require any special-casing.<p>If you're compliant with web standards and the web page renders badly, then any problem reports are generally browser bugs. With that as a starting point for the ensuing discussions, you can then decide if you want to add support for the (buggy?) browser, or request that the accessor upgrade or migrate to a more standards-compliant browser.<p>Of course test harnesses can and do help here. But the closer you stay to the W3C and applicable standards, the more bug-resistant and future-proof your web site is, and the less browser-tail-chasing you will likely need to do. And the less point testing you can need to fund, particularly as you build confidence in the standards and the core browsers.<p>As for reading material, a subscription to communitymx.com is well worth the costs; that's one of the better HTML and CSS-oriented sites on the net.