Access my site offline? Seriously newby ?

Oh lord this is probably a really basic (dimwitted) question. But thanks for any help.

Ok I have new site hosted at DreamHost (www.highwayhags.com). WordPress is working on it just fine. I’ve even made a couple of posts to make sure all is well. The thing is that I would like to be able to fiddle with the site on my computer — without being on the internet — then just upload changes. We are truck drivers and internet access is unpredictable.

I downloaded FileZilla which is cool, then I downloaded WordPress to my computer. I changed the config file as requested and it said it appears you have already uploaded WordPress. But how do I make it where we can access the site off-line?

Thanks so much for any help,
Hedon