To get the scan to your new machine a USB thumb drive would be the simplest way. Scan on the old machine and transfer to the new. Or if you have a CD-RW in both machines you could format a RW using packet writing to use it like a big floppy to transfer files. As far as I know scanning does not work over a network anyway.
To share the printer you have to network your computers. A crossover cable would be the easiest/cheapest(about $10) way to connect the computers since you don't need internet access on the old machine.
What I do is I have my machines networked with a router but only one machine setup to share files. I have the printer/scanner hooked up to that machine, and have the scanner set to save to a shared file, then I can get the file from any computer in my house.
As already stated a KVM (Keyboard,Video,Mouse) switch will work for the rest.
8 Pro 64bit
AMD FX 8350
Asus Sabertooth 990FX R2.0
16GB G.Skill Sniper 1866MHz
OCZ Vertex 4 128GB SSD
HDD's 750GB x2/500GB/250GB
2x XFX 6870 1GB
PC P&C 750W PSU
Cooler Master HAF 932 Red LED
CM Hyper 212 EVO w/2x SickleFlow 120mm Red LED
Logitech X540 5.1 Surround
2X Acer 23" LED - Eyefinity: 3840x1080
"The significant problems we face cannot be solved at the same level of thinking we were at when we created them."
- Albert Einstein