gastrocnemius wrote:

What does this mean? How, where and why do I do this? Do I pick one, or all of them? (And yes, I read the 'more information' file, which was equally mind-boggling):

"Once you've uploaded all the files you can set the permissions of certain key files using your ftp software. Assuming your b2evo is installed under /blogs. Here's what you would need to change:
chmod 666 /blogs/conf/_basic_config.php (_config.php before version 1.8) if you want the installer to be able to automatically update your config based on your input.
chmod 777 /blogs to allow creation of blog stub files from the admin interface or to generate static pages for your blogs.
chmod 777 /blogs/media in order to upload images and other media from b2evo's backoffice.
chmod 666 /blogs/skins/custom/* if you want to use the template editor for the custom skin.
Here is more information on setting directory and file permissions (especially about not using mode 666, but 600 or 660, if possible!). "

You have answered your own questions:

chmod == change file permissions
How do I do this? == using your ftp software
where = on the files youve uploaded

In a nutshell:

On computer filesystems, different files and directories have permissions that specify who and what can edit and read them.

Using an FTP Client:

FTP programs ("clients") allow you to set permissions for files and directories on your remote host. This function is often called chmod or set permissions in the program menu.

Lots more info can be found via Google:

http://www.google.com/search?hl=en&as_sitesearch=forums.b2evolution.net&q=chmod