This would be coolant that is leaking?

If so, doing it yourself shouldn't be too hard. There are really only
two going to the engine from the radiator. Since you see coolant near
the pulley it is probably top hose but inspect both.
Follow both hoses from the radiator to the engine and wipe them clean.
Then start the engine and see where it is coming from. Perhaps do this
after the engine has not run for a while (like overnight) so that the
coolant will not heat up too much.

To replace the hose, you will have to drain the coolant from the
radiator. If the top hose is bad, you'll only need to drain a little -
just enough so that the coolant is no longer present in the top hose.
If the bottom hose is bad, you may need to drain the complete system.
You'll find a drain cock on the bottom of the radiator. Catch the
coolant in a container, being careful not to burn yourself as this can
be very hot. (if the engine has just been running that is).

After is has drained, loosen the clamps, replace the hose and refill
the coolant you let drain out.

Also, be careful spilling the coolant - Clean it up. Besides it looking
messy in your driveway, dogs and cats seem to like to drink it. Most
coolant is poison, so you don't want that to happen.