The official campaign website is the first result for me, but Google search results are different for everybody.
Personally, I think it's better if the website doesn't use Flash, because it's still an unsupported media type for many mobile devices (e.g. iPhone, Blackberry).
Anyway, I'm sure there's more to be said about the site's design, branding and organization... Personally I would like to see more colors, and tighter spacing between the various page elements... but in the long run, I think it's the content that's lacking the most.
FWIW, here are some of my thoughts on ways the official website could improve:
1. Add more photos of supporters, and Ron Paul interacting with them
In 2008, the average voter's perception of Ron Paul could be summed up by this phrase: "I don't want to throw my vote away." The campaign needs to show more photos of Ron Paul interacting with people to help counter the perception that he doesn't have any real support. As it is now, the one photo of Ron Paul on his bio page makes him look rather lonely, don't you think?
2. Focus on the grassroots
Barack Obama's 2008 campaign was successful largely in part due to it's focus on getting people involved. The "Hope" message was catchy, but think about this: when you go to Obama's website, one of the first things you'll see is a "Get Involved" message. In fact, ways to get involved are all over the main page, not just news. This really made Obama look like the "people's choice" compared to every other candidate (see my first point).
3. Focus on educating visitors about Ron Paul's principles, not just the issues
I dare say that Ron Paul's supporters are much better informed about the issues than any other candidate's. However, the issues aren't really what define us... it's the principles we believe in that make those issues important. This is why a lot of people still don't "get" Ron Paul; they don't have a mental framework, or worldview, to process the information we give them. The website needs an "Issues" page, I agree. But it isn't enough. We need a "Principles" page too, with links to resources where people can get educated. Personally, I think the Mises Institute is a great start.
Edit: Now that I'm thinking about it, someone should make a dramatization of "That Which is Seen, and That Which is Not Seen."