I wonder how pro photographers use aperture?I shoot raw and my harddrive is alreay full.I'm not able to import new pictures.Is it ok if i create a vault and delete all my projects in the HD.Can I use an external HD use aperture through the vault??

There's a bit to learn. It will slowly make sense.

Aperture is an empty field. You're given a tractor and a whole bunch of attachments. What you grow, how, and where, is entirely up to you.

Vaults are for back-up and only for back-up. They have nothing to do with storing your working files.

When your Library outgrows your system drive (and for good performance, you should leave c. 20% of every drive empty), it's time to convert some of your image's Masters from Managed to Referenced. ("Managed" and "Referenced" refer to Masters, not to Libraries.)

There are hundreds of posts in the forum, and several pages in the User Manual on using Masters.

Many people run Aperture with the Library on their system disk, and most (or all) of their images' Masters on external FW drives. This is a good set-up. Note that you will likely have to take steps to back-up the data on your external drives.

If you do the above, there should be no reason to delete any Projects.

The choice of RAW or RAW+JPEG or JPEG depends on the kind of work you are doing. I capture RAW only -- but I don't do any commercial shoots. Pros on deadlines report that the RAW+JPEG works well for them. Capture JPEG if it saves you time. IMHO, there is not a good reason to shoot JPEG to save space (space is cheap; time expensive).

Short-term solution: buy and use a FW800 external 1 TB drive, formatted "Mac OS Extended (Journaled)", and using Aperture relocate the Masters of all images older than 30 days to that drive. (Be sure to change your back-up strategy to include this new drive; you may need a second new drive.)

This general post of minemight help you understand more about Aperture.

And if I may emphasize on a point Kirby made: never ever delete Projects!!!

Projects are where your pictures are stored in Aperture's database. Deleting projects not only threatens your files depending on your setup, but it most certainly destroys all the work done on those photos in Aperture: adjustments, metadata etc.

I'm like Kirby and work pretty much exclusively in RAW. I use a referenced library with files stored on external FW800 RAID drives. Vault for library backup (which doesn't contain the actual files) and a separate backup solution for the data drives.

Believe me: one of the great strength of Aperture is its ability to manage lots of files.

I work with a Mac Pro, and have the complete, Managed, Aperture Library (makes backup very fool proof) on a separate internal hard drive -- currently one that is 2 TB, while the Library is only approaching 800 GB. With the option to have multiple internal drives, I prefer the library to entirely be separate from the boot drive -- this much like the recommended configuration for Final Cut Pro use. If only a single internal drive, I would op for putting the library on an external FW800 drive, possibly only the Masters of a Referenced Library. With the advent of Thunderbolt on the newest iMacs, and with availability of those drives, I probably would again use Managed libraries on that external drive.

Ernie