Logotype - I'm assuming this is a custom font. The letter widths seem a touch awkward, The O is a little to wide, the Y could be a tiny bit wider, K/T/H should be about the same and the E should be narrower than those 3, not wider. The kerning could also do with some work, specifically the I is too close to the E (almost looks like an 8 on a digital watch). Check out some similar fonts to compare their widths and kerning. Your favicon also seems to use a different font, although that's probably nitpicking
Nav - I'd drop the italics. Italics on small text just looks pixelated and a PITA to read. This can also be exacerbated by using a light font, such as Raleway that you have employed here. Unfortunately browser text rendering is not always that great across different browsers and OSs.
Header drop shadow - seems a bit to dark to me. About 30% opacity should be fine: replace 'black' with rgba(0,0,0,0.3). Subtlety with drop shadows is key, otherwise they just stick out like a sore thumb - they are just an accent, rather than a major design feature.
The padding on the images div is causing a second horizontal scrollbar (Chrome/Win7). I don't think you need that padding (which could be truncated to padding: 0 30px; if you do).
I'm assuming you'll also be setting up a js carousel for the images and not keeping them as they are - manual horizontal scrolling is not that user-friendly. At the very least, you could look into using a jquery plugin to scroll horizontally using the mousewheel. A quick search brought this up (a little old): Scroll Page Horizontally With Mouse Wheel | CSS-Tricks. Just attach the behaviour to the image div and not the body should work, though not tested.
I think you'll also have a hard time promoting the site, SEO-wise at least, due to the lack of descriptive image names, alt attributes, descriptions and long-descriptions. You definitely want to sort that out for the logo otherwise there's very little for search engines to index.
I've addressed the logo issues and navigation text. I haven't concentrated on SEO yet really so that's not so much of an issue yet.
The client liked the idea of having horizontal pages for the images (she had seen it on another website) so I didn't actually have any intention of using any JS. I've implemented the mouse wheel code you suggested, but not sure if it actually works when applied to a class rather than a 'body' tag (i'm using a MB Pro which scrolls horizontally anyway).