Andrew's was a relative path, assuming you would understand that User was your Home. I normally just say your user/whatever since the default locations on the Finder Sidebar point to the user's home folder.
Depending on when your iPhoto Library was created, it may or may not have the .photolibrary extension. That is new with Mountain Lion. Migrated libraries will not have the extension, hence a majority of the replies to your question would be just, "your user/Pictures/iPhoto Library."
For unix, ../ means go up a directory level. So, you would have had to be in the iPhoto Library directory for that path to work.
Without a starting /, it is a relative path from your current working directory. Starting with a / means start at the root of the hard drive.
~/ means your Home directory, so you may see that notation occasionally. E.g. ~/Documents , ~/Pictures, ~/Library
Speaking of ~/Library (your user/Library). That folder is hidden. To get to it, you must hold down the option key and select Library from the Go menu. You can unhide it, but I haven't found much of a reason to dig around in there. Most of the time it is just troubleshooting.
Getting back to the iPhoto Library, digging around in that folder will likely damage the iPhoto Library database. If you don't want to let iPhoto handle file manipulation, you can set it not to copy images into the iPhoto Library. It will index them externally. You can do everything from within iPhoto that you can do moving files around. If you need an actual file, say for uploading to a website, just drag the photo from iPhoto into the open file dialog and it will point to the file. Or, you can right-click and reveal it in the Finder.
Can we stop the bashing now? it is counter productive.
Oh, I thought you wanted to be treated that way. I always figure people want to be treated the way they treat others. Given your namecalling and curt, arrogant responses to others, I thought you wanted us to treat you that way, too.
