How can I make my website accessible for someone who is blind? I would like to do this, any advice?

I've never done one but I think if you put audio on the various elements of your site, blind people can navigate and listen to your site using specialist equipment instead of viewing it.  If you have a look at the web site for the RNIB, they will no doublt have information there or can provide it if you contact them.

Thanks lotusleaf, I will try the RNIB. Moonfruit have told me that as the sites are built in Flash it is not possible for software like this to read the text on my site.

Due to the flash content then it is seemingly impossible to make the site 'accessible' hmmm how does that help people with disabilities

Presumably you mean people with visual disabilities?  I wouldn't say Flash makes it impossible - making the site more accessible to visually impaired people could be as simple as using bright or dark colours;  also high contrast colours;  also large and well-spaced lettering. 

I would much rather have a site with no flash content

That would be impossible on a moonfruit site as the infrastructure is Flash-based.  That's what makes it so easy to use and enables users to create such great-looking sites.  You pays your money and you takes your choice.  Unless you've got a free moonfruit site, in which case, you've lost nothing.

especially as it also means the sites look poor on all apple devices (and there are a LOT of people who use those).

Yes, I'm one of them - I have a desktop Mac, a laptop Mac and an iPhone.  It simply isn't true to say that "the sites look poor on all apple devices".  On desktop/laptop Macs, the technology used to build the site makes no difference whatsoever to how it appears. The Moonfruit package is sophisticated enough for members to use their creativity if they wish, and many Moonfruit-created sites look fantastic.  For iphones, Moonfruit has just launched a Mobile Editor tool which enables the mobile version to be configured differently from the desktop site - I've worked my way through most of my clients' sites now and it's brilliiant.  I'm really happy with how they look on iPhones now.  The only device left is iPad, and when Moonfruit launch HTML5 later in the year, I expect my sites to look just as good on iPads.

Another thing that helps visually impaired people to read web sites better is putting text over a plain background rather than a patterned one.