If you have special characters in your language like ñ, á, é or æ, ø, å it's safest to use utf-8 all over.
Here's a setup that works for me:
In your PHP page, use utf-8 as your charset like this:
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
In your MySQL database:
Use utf8 -- UTF-8 Unicode as your Character set and utf8_yourlanguage here_ci as your Collation
In your connection string:
Add this line at the end of your connection string: mysql_query ('SET NAMES `utf8`');
Hope that helps.