Do I need any special tools to swap this in?

A socket set, basic wrenches, and a jack with jack stands will get you through it. Some people use a bearing puller if the old unit is stubborn, but it's not always necessary. Your Sable's service manual will walk you through the exact torque specs for your year.

Will this come with new lug nuts or mounting bolts?

This is the hub and bearing assembly only. You'll reuse your existing lug nuts and mounting hardware. If any bolts are damaged during removal, grab replacements from a fastener supplier before you install.

How do I know if I need the front or rear hub?

Front and rear hubs look different and bolt up differently. If you're not sure which one you need, check your vehicle's service manual or measure the bolt pattern on your existing hub before ordering. Putting the wrong one on won't fit.