how to share a common monitor, kb and mouse between a PC and imac?

The best way of doing this is to get what is known as a KVM (Keyboard, Video, Mouse) switch box. The model will depend on how many computers (in your case 2) and the type of connector the monitor uses. The best choice will likely be to use DVI for the monitor connection. An example product is below.

http://www.amazon.com/StarTech-Switch-Cables-Audio-SV211KDVI/dp/B0017JY5EU

The Mac mini will need either a Mini Displayport to DVI adaptor or to use the HDMI to DVI adaptor it came with. If the monitor is a larger higher resolution one then you will need a Mini Displayport to Dual Link DVI adaptor and such monitors will not work with the HDMI to DVI adaptor. See the following

http://store.apple.com/us/product/MB570Z/B/mini-displayport-to-dvi-adapter

http://store.apple.com/us/product/MB571Z/A/mini-displayport-to-dual-link-dvi-ada pter

The other option, which will save even more space, is to install Parallels or VMWare Fusion on the Mac and then install Windows as a VM and migrate the Dell's Windows install to it. You can run the VM from an external HD, and get rid of the second computer altogether.

I have Windows XP, Vista, 7, 8 & 8.1 as well as OS10.6, 10.7 & 10.8 all running as VMs. So basically, I have nine (9) computers in one. That's a lot, but I do software testing and web design all day so I need to be able to test in numerous environments.

But if you could run both OS's from just a mini, with one monitor, one keyboard and one mouse for everything, and no tower necessary for the PC it'd be even tidier.

Hi. I'm going to buy a Mac Mini and a cheap-o monitor and hook the Mini and my wife's work computer up to the monitor via a KVM switch. Will this work with the following equipment? Is there anything more I need? I've never done this and am kinda lost. Thanks for your help.

Mac Mini: http://store.apple.com/us/buy-mac/mac-mini

Monitor: http://www.amazon.com/dp/B005BZNDOO/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&coli d=2D1FPPUUDP6M6&coliid=I3UG5KZS1KAEX4&psc=1

KVM switch: http://www.amazon.com/dp/B002K0TU2C/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&coli d=2D1FPPUUDP6M6&coliid=I3E1WR5OV3BCX6

Wife's work computer: http://shop.lenovo.com/ae/en/laptops/thinkpad/edge-series/e530c/

Hi. I'm going to buy a Mac Mini and a cheap-o monitor and hook the Mini and my wife's work computer up to the monitor via a KVM switch. Will this work with the following equipment? Is there anything more I need? I've never done this and am kinda lost. Thanks for your help.

Mac Mini: http://store.apple.com/us/buy-mac/mac-mini

Monitor: http://www.amazon.com/dp/B005BZNDOO/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&coli d=2D1FPPUUDP6M6&coliid=I3UG5KZS1KAEX4&psc=1

KVM switch: http://www.amazon.com/dp/B002K0TU2C/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&coli d=2D1FPPUUDP6M6&coliid=I3E1WR5OV3BCX6

Wife's work computer: http://shop.lenovo.com/ae/en/laptops/thinkpad/edge-series/e530c/

Also, I'm assuming she won't be able to use her Apple keyboard and mouse with this set up. Any suggestions on a keyboard and mouse that is compatible with Apple and Windows?

All PC USB KB and mice are compatible. If the devices have programmable functions keys those ill not owrk unless the manufacturer provides Mac drivers.

Here is how to use the Mac-only keys on a PC KB

Keyboard mappings using a PC keyboard on a Macintosh