Linking mac book air with iMac

[Dafydd]

I need help. Please bear with me, I'm a builder and not an IT guru.
i have an iMac in the office upstairs. I use this generally for typing quotes and invoices. I have 2 folders on the desktop named invoice and quote.
i have bought a MacBook Air. To enable me to add to these files and edit them from downstairs (we have an 8 week old son and I feel rude sat up stairs all night).
i can't figure out how to share these folders. Can anyone help ( I am a spaz)
cheers

 

[TheEvilGiraffe]

Right click or CMD+click .. Share .. AirDrop.

 

[Rob]

I'd have said dropbox. Simples.

 

[Dafydd]

Many thanks guys. I'll give this a blast. Will this keep the master on the I Mac and just let me alter them on the MacBook Air?
cheers daf