Here's my general critique, mostly about layout and fonts. A few image critiques as well. I second Sozobe's recommendation for Site Kreator. Your website isn't very complicated and would be very easy and not time consuming to convert to Site Kreator. I'd even volunteer to get you started and do the basic set up for you. You'd also have a lot more features available to add to the site. You also might consider Bravenet. (Both are free and both have the option of webpage templates or do-it-yourself. Both also have expansion capability for a fee.) Bravenet takes a little more knowledge of html, but not much. It has a little more layout flexibility than Site Kreator and is very compatible with Blogger. The draw back is that it is mostly add-on modules and you'd have a bit of work setting up all those.
Either way, once done, neither would require much further maintenance other than content changes. Here's my critique. My offer to help is there if you'd like it.
Home page:
The font style being used is very difficult to read, especially when in smaller size. Switch to something more easily read like Arial, Veranda, Trebuchet MS. The shaded background and similar font color also makes it difficult to read as the font shrinks in size. You need to have a sharper contrast between the two. You might consider eliminating the shaded background and using borders to separate/highlight areas of text. That will also help reduce the "monotone" look of the page.
Images: You need a more stylized arrangement of images and text. It just looks unorganized and cluttered. The images need to be cropped to emphasize the focus of the picture rather than including all the background trees. Image sizes should be enlarged or make them clickable thumbnails that people can click on to see a larger view. They are too small for anyone not familiar with the content to have an idea of what they are photos of. For a more professional look, add a narrow border around the images.
Header: Love the logo and font style for the header text. For the address and "former" lines, switch to lower case rather than all caps. The font you are using is difficult to read in the smaller font sizes. Rather than changing the font style, switching to lower case will make reading it a lot easier.
Navigation/menu bar: Any possibility of adding a bit of a border to this area to have it stand out from the other text on the page? Consider alphabetizing the menu items so they are easier to locate when searching for an item to navigate to.
Right-hand column of text: Add an extra blank line between paragraphs to give it more "white-space." It appears as one massive block of text without it and many people just won't read it because of that. Turn off justification and let the text flow naturally.
Left-hand column of text: Layout consistency is a problem here. Everything else on the page is left-justified. The items in this column are all centered and it just gives a ragged look to it.
Carry the colors in your logo throughout your color scheme. Use the green and browns to change font colors when emphasizing portions of the text. Maybe alternate font colors for the various country labels for people to click on.
Content: Give people a reason to keep coming back to your website. Have a space on the front page with information that is constantly changed/updated. Use the Projects area for this. Give periodic updates and status snapshots of the projects and not just an overall description of the project. Consider embedding a blog on the homepage for this purpose to post updates and any newsmedia reports related to your organization and projects.
Graphic: Consider using the olive branch portion of the logo image as a divider/eye-catcher/space filler. It will help break up the text a bit and provide some color contrast. Here's an example:
Board page:
Good. Any possibility of adding a small head shot image of each board member to go along with each bio or at the top as a collage? If not, consider using the leaf graphic as a divider between each bio.
Methodology page:
Good use of white-space. Consider making the layout more consistent. Everything is left justified except for the image and caption. They are centered. Change image and caption to left justification. Add a border line to the image if possible.
About Us page:
Excellent. Use this as a model for your Board photos on the Board page.
How to Help page:
Lots of info on this page that should be more prominent and easily found via the home page. You don't know it exists until clicking on the How To Help page. Add a clickable text box on the Home page for Fellowships and another for donations.
Reading Room page:
Any possibility of adding a two-line description of the papers to entice readers to click on the report title?
I like the layout on this page and the use of background shading.