Hi,
make sure you have "Dconf-Editor" installed first, also you can use the "Gnome Tweak Tool" which is also not installed by default!.
Change global font size:
Dconf Editor > Org > Gnome > Desktop > Interface > Text-scaling-factor 1.0 (1.0 = font size 10. and 1.1 would be font size 11 and so on) (Mine is set to 1.2 = Font size 12)
Or:
(Gnome) Tweak Tool > Fonts > Text Scaling Factor
To install both apps in a terminal, paste this command:
sudo apt-get install dconf-tools gnome-tweak-toolTo change the page fonts in Firefox, simply press Ctrl and the plus symbol (+) which will increase the fonts and everything else, or you can globally set the font size in Google Chrome via the settings manager and it is permanent.
Regards Wolfman