How do I transfer files from my current imac to the new one. My old imac is running 10.5.8

Hello

I got a new iMac 10.8.2 and also have a iMac 10.5.8 how can I conenct those 2 ?

All I want is to use some of my files on my new one.I don't want to transfer ALL my files,just some,like pictures. But only the once I need. Not all of them.

I have a FireWire cable,don't work, I have ethernet cable,don't work.

So I must do something wrong 😊 If someone could maybe explaint it to me step by step that would be great,since I am not a big Mac (computer) freak.

So basically I would like to use my old iMac as a external drive where I could get my files from and transfer them to my Mountain Lion, iMac.

Also If someone knows,why Mountain Lion always loses internet conections,would be also a very big help! 😊 Thank you!

But please, in simple step by step explaining. My english is not the best,my German is much better 😉

Thank you so much already for the help, I really appreciated!