Is upgrading from OS X 10.4.11 to OS X 10.6.3 possible and a good idea?

Yes, it is possible.

Whether it is a good idea or not is something only you can decide.

Personally I see be so far behind as a problem primaily from the security aspects of it.

If Snow Leopard 10.6 doesn't offer you anything then you might want to stay there.

Allan

To upgrade to Snow Leopard, you will have to purchase the Snow Leopard install DVD from Apple

Then upgrade

A backup first is a great idea

Then if your Mac will support Mavericks you can upgrade to it

To answer that either you will have to research what your Mac can run or provide the details as to exactly which Mac you have and someone here can look it up for you.

First thing you need an external disk drive to receive the backup.

If you don't have one, a good place to look for one is at https://eshop.macsales.com/shop/firewire/

Then you can do it either with Time Machine which is built into OS X after 10.5 which will not help you right now.

The other choice would be to use either CCC or SuperDuper. They will create a bootable clone of the hard disk drive.

Sorry that MBP is not capable of running anything beyond Snow Leopard.

Allan

MBP is short hand for MacBook Pro.