The width of your blog is made up of three parts; the entire width of your blog, the posting area, and the sidebar(s). To put it into perspective: width of your blog = posting area + sidebar(s) .
To find the width of your blog search for this piece of code(or something similar):
To find the width of your posting area search for this bit of code(or something similar):
To find the width of your sidebar, search for this bit of code(or something similar):
Feel free to play with the codes to get your blog width how you like it. Just make sure to keep your blog in proportion by following the equation: width of your blog = posting area + sidebar(s) . Also, if you have padding between your posting area and sidebar, you need to include that in your equation.
(can you tell I've been doing Algebra this morning?! =P)
If you have any questions, let me know!
Just so you know, I wrote several tutorials(including one covering blockquotes) last week. When blogger had it's little glitch, I lost all of those posts. Sooo....I don't really feel like rewriting them all over right now, but they are on the list. Gotta love technology sometimes, huh...