Here's a link
with things you can do from the grub prompt.
To really help you, we need to know more about what partition/OS you want to boot and whether you want to restore grub or erase grub totally.
You most likely deleted a partition that had grub's config files. So the first part of grub lives in the Master Boot Record and then looks for it's config files on some partition to see what it should do next. Since it can't find them, it just sits there until you tell it what to do.