I don't use a particularly small font. I find that emacs works great -- switching between buffers, toggling between marks, bookmarks, etc., is extremely easy, and some chords are easier to type b/c of the keyboard design.
I have the font size set to 10pt which seems to be about the right size. I would probably use that size even on a larger monitor. Subpixel rendering and the LED backlight on this netbook (plus a nice emacs color theme) makes the text read very easily.
For documentation, I just open it in a web browser and switch with alt-tab or ctrl-tab (within the browser).