Hi,
Below are some points which should be checked in web based application :
1. GUI (Font, Control Alignment, Control Size, Spelling, resolution etc.)
2. Performance-response time (Page should be displayed/refreshed within certain period of time)
3. HTML tags in text box / text area.
4. Security Testing (e.g. Save the URL, Clear cookies, paste the URL in new browser window, it should not allowed to open, should redirect to login/default page, also Cookies verification), Annonymous Access (Hacking)
5. Link redirections or dead link verification