Even if the prospect of asking a girl out on a date makes you nervous, don't be concerned!
1: Make a plan for where and when you want to go on your date. Don't just say you'd like to "hang out" with her.
2 : Go up to her and ask her. While it may be tempting to ask her out through the phone, text, or the Internet, doing so will prevent you from communicating with her nonverbally.
3: Seek assistance from a common friend. If you're still having trouble approaching her, enlist the assistance of a common friend.
4: Be explicit about your aims. You don't have to tell her "this is a date," but you shouldn't keep your sentiments hidden.