my mac book pro has got 41 GB of other stuff on it clogging it up how do I find out what is rubbish and delete it

For information about the Other category in the Storage display, see this support article.

Empty the Trash if you haven't already done so. If you use iPhoto, empty its internal Trash first:

iPhoto ▹ Empty Trash

Then reboot. That will temporarily free up some space. Do the same in other applications, such as Aperture, that have an internal Trash feature.

According to Apple documentation, you need at least 9 GB of available space on the startup volume (as shown in the Finder Info window) for normal operation. You also need enough space left over to allow for growth of your data. There is little or no performance advantage to having more available space than the minimum Apple recommends. Available storage space that you'll never use is wasted space.

If you're using Time Machine to back up a portable Mac, some of the free space will be used to make local snapshots, which are backup copies of files you've recently deleted. The space occupied by local snapshots is reported as available by the Finder, and should be considered as such. In the Storage display of System Information, local snapshots are shown as Backups. The snapshots are automatically deleted when they expire or when free space falls below a certain level. You ordinarily don't need to, and should not, delete local snapshots yourself.

See this support article for some simple ways to free up storage space.

You can more effectively use a tool such as OmniDiskSweeper (ODS) to explore your volume and find out what's taking up the space. You can also delete files with it, but don't do that unless you're sure that you know what you're deleting and that all data is safely backed up. That means you have multiple backups, not just one.

Deleting files inside an iPhoto or Aperture library will corrupt the library. Any changes to a photo library must be made from within the application that created it. The same goes for Mail files.

Proceed further only if the problem isn't solved by the above steps.

ODS can't see the whole filesystem when you run it just by double-clicking; it only sees files that you have permission to read. To see everything, you have to run it as root.

Back up all data now.

If you have more than one user account, make sure you're logged in as an administrator. The administrator account is the one that was created automatically when you first set up the computer.

Install ODS in the Applications folder as usual. Quit it if it's running.

Triple-click anywhere in the line of text below on this page to select it, then copy the selected text to the Clipboard by pressing the key combination command-C:

sudo /Applications/OmniDiskSweeper.app/Contents/MacOS/OmniDiskSweeper

Launch the built-in Terminal application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad. Click Utilities, then Terminal in the icon grid.

Paste into the Terminal window (command-V). You'll be prompted for your login password, which won't be displayed when you type it. You may get a one-time warning to be careful. If you see a message that your username "is not in the sudoers file," then you're not logged in as an administrator.

The application window will open, eventually showing all files in all folders, sorted by size with the largest at the top. It may take a few minutes for ODS to finish scanning your files.

I don't recommend that you make a habit of doing this. Don't delete anything while running ODS as root. If something needs to be deleted, make sure you know what it is and how it got there, and then delete it by other, safer, means. When in doubt, leave it alone or ask for guidance.

When you're done with ODS, quit it and also quit Terminal.

Files that show up under the Other Category are Not Rubbish files and they are not Clogging up your Memory. They are taking up hard drive space but 41 GBs is practically Nothing.

Files that are in the Other category are many System, Operating System, files and other files that do not fit into one of the other Pre-Defined Categories.

This is my hard drive with 2 partitions. One for Mt Lion and the other for Mavericks.

You see I have 90.5 and 59.1 respectively of Other Files on each partition. And I don't worry about it. Which is what you should do, IE Stop worrying about the Other category.

If your drive is filling up it is from some other files you are placing on it and not what is listed in that Other Category.

I wish Apple would drop that screen as it always leads the Uninformed to the same assumption. That is the Other category is taking up all the HDD space.

OS X is constanly creating it own files, like every second, and most of those are log files which don't take up much space. But over the long run can add up. you have to realize that OS X and the included iLife apps by themselves takes up around 15-25 GBs of space and that is not including the sleep image file which is the same size as the amount of RAM installed. Then you have the Time Machine Local Snapshots which will fill the drive to around 80% full before any of them are deleted.

Download and run OmniDiskSweeper and post a screen shot of it.

You can download ONYX and it will do what you want but I suggest you be very very careful when using it. This is a free software but it is very very powerful and you had better KNOW WHAT YOU ARE DOING while using it. It will clean up your Mac.

And I would fool with ONYX. It is a good program but used improperly can really screw up a Mac.