SVN checkout ignore folder

You can't directly ignore folders on a checkout, but you can use sparse checkouts in svn 1.5. For example:

$ svn co http://subversion/project/trunk my_checkout --depth immediates

This will check files and directories from your project trunk into 'my_checkout', but not recurse into those directories. Eg:

$ cd my_checkout && ls
bar/ baz foo xyzzy/

Then to get the contents of 'bar' down:

$ cd bar && svn update --set-depth infinity

Yes, Subversion 1.5 has a feature called Sparse checkouts that can do exactly this sort of thing.

No, ignore is only for adding files.
You can use sparse checkouts (if you use svn 1.5)