You can give your blog (or any website) a readability test
Below are the results for this blog.
(Note: The script only computes the results for the page you provide...it doesn't search your archives. Therefore, to find the URL I would enter, I clicked on the 2008 archives link in my sidebar.Reading Level Results
This is the URL: http://transylvaniandutch.blogspot.com/search?updated-min=2008-01-01T00%3A00%3A00-06%3A00&updated-max=2009-01-01T00%3A00%3A00-06%3A00&max-results=50
If you ignore the gobbledygook, you can see there are three variables that are easily modifiable - a beginning date, an ending date, and a maximum number of posts. I made the necessary changes so that every 2008 post of mine would appear on one page. Therefore the statistics below represent my average for the entire year so far.)
Total sentences 5180
Total words 49461
Average words per Sentence 9.55
Words with 1 Syllable 32003
Words with 2 Syllables 9804
Words with 3 Syllables 5252
Words with 4 or more Syllables 2402
Percentage of word with three or more syllables 15.47%
Average Syllables per Word 1.56
Gunning Fog Index 10.01
Flesch Reading Ease 65.48
Flesch-Kincaid Grade 6.50
My blog falls somewhere inbetween 6th and 10th grade level reading. I consider that good. I wouldn't want my writing to require higher than a high school education to read. Supposedly it is roughly equivalent to the readability of Time and Newsweek.
Flesch Reading Ease is a 100 point scale, the higher the number the easier it is to read. 60-70 is a recommended target, which I seem to fall smack dab in the middle.