What is the most common size monitor these days?

I'm in the process of redesigning my website. I've done a few galleries and final image pages and they look great on my 26" widescreen monitor. However they are way too large for my wife's old 17" screen and a little bit too large for my 14" widescreen laptop. They work well with my daughter's 22" widescreen.
I know there are web authoring software programs that enable a person with the requisite knowledge to design web pages that come out centered on any size monitor. However, I don't want to spend the money and the time needed to learn how to do it. I use Photoshop's ImageReady software which does all the coding for me (good thing since I know nothing about coding) but at the same time does not allow any user to mess with the coding produced. I've thought about Dreamweaver but Adobe is sure proud of that program and I'm not sure I would be able to have the time needed to learn it anyway. I wish there was something out there that is as user friendly as ImageReady, but with access to more features that would still be as easy to use without needing coding knowledge.

Here's a couple of samples of what I'm talking about: www.freshairphotos.com/brtn.html
www.freshairphotos.com/bmtn.html

I have to scroll side to side to see all of the page on my 17".

The scroll bar appears when using my 24" monitor, but there's nothing in that area that is visible except the background color. It's just a bit disconcerting because when the scroll bar appears, I'm naturally inclined to check it out.
The pages themselves are nicely centered without scrolling.

Same as John on my 24". I would design your page for a 19" monitor at the largest. The content looks great though.

FYI, just one of the resources for internet usage stats ...
http://www.w3schools.com/browsers/browsers_display.asp

I still recommend designing for a 1024 x 768 max resolution, but that number is getting closer to extinction. I certainly wouldn't produce any fixed layouts over 1200 pixels wide. I use 1920x1200 on my 26" monitor, and I see both horiz/vert scrolling ... because your ImageReady header slice is 1945 pixels wide. That's simply way too big. If I knew anything about ImageReady, I'd offer some help. Sorry! Your current website was produced with ImageReady, it appears, so I'd suggest adapting your new colors/header to that old layout.

You might consider hiring a coder to generate a simple one-page template from your design - something you could use to create other pages. Yeah, more time involved. But that, and a cheap/free HTML application, would be the most affordable/compliant method of achieving your custom look.

As far as what most people are buying, I work for a large computer store and I would say the vast majority are buying 22" and above. You can purchase an Acer 22" for as low as $109.00 so they are very affordable. I agree with what Jesse says about designing for 1024x768 since a lot of people with laptops have smaller screens.

Ditto what Jesse said... 1024x768 is still the most common for the non-techie, non-photographer group. Best practice is to design for the lowest common resolution practical. This allows everyone the best view of your work. I try to stay away from horizontal scrolling of any kind. Some artists and designers like it, but usability studies still prove that it is not intuitive for the general viewer. BTW, very nice design!

Thanks everyone for your thoughts, I really appreciate it. I think I'll try to compress the meat of the pages inside 1200 pxls width with the dark background at 1900pxl to eliminate white areas on larger monitors, which will mean hz scroll bars.