how do i debug a website that looks weird on opera mini? The site is working fine on any other browser
Alas, I know of no dedicated resource on how to debug a website w/ Mini, though there are a few related articles on http://dev.opera.com that might help you. The most recent article is A developer's look at Opera Mini 5, but Making Small Devices Look Great and Designing With Opera Mini in Mind should be particularly useful as well.
Generally check how a site looks in Opera Desktop and use Opera Dragonfly for debugging. Another good tool for debugging is MicroEmulator when used w/ a locally downloaded version of Opera Mini and a resizable skin.
Also, there is a special url in Mini that allows you to access the ECMAScript error console: just type "debug:console" in the url field. You can combine this with calls to opera.postError() in the development version of your site to post any string to that console. However, it won't show you html tags.
I could probably help you better if you had a more specific question.
You can do remote debugging of Opera Mini (or any Presto-engine-based browser instance on any device; computer, smartphone, set-top console, SDK) via Opera Dragonfly from Windows, Mac, or Linux. The Dragonfly console is open-sourced and built into Opera v10.5x.