If you need to show or hide hidden files in Mac OS X (like .htaccess or anything else starting with a "."), copy and paste the following into a terminal window, then hit Enter:

Show:
defaults write com.apple.finder AppleShowAllFiles TRUE
killall Finder

Hide:
defaults write com.apple.finder AppleShowAllFiles FALSE
killall Finder

Warning: that second line makes all open finder windows close.

Hint: The Terminal is an application that is accessed from Applications > Utilities > Terminal.  Alternatively, you can perform a spotlight search for "terminal" and it will likely be the first result.