By “UW,” you mean unweighted? If so, I don’t think of that means anything for transfers. All that matters are classes you take that are UC transferable, which will make up your GPA.
If you search, beyond the Haas website, you’ll find plenty of websites made by Haas students either when they were in or when they got out. There’s also the Haas undergad student blog. A ton of posts on Ms. Sun’s website. There are are million posts on here and elsewhere about it. You just have to get creative with Google.
Regardless, it’s all pretty basic … get great grades, be active on campus and in the community, complete all the required courses, and present yourself well in the three essays, showing them why you are unique and why your experience/background will make you a valuable member at Haas.