equipment

What "equipment" (thermometers, medicines, etc.) do you really need to have on hand for your new baby or for your children?

Newborn:

thermometer, preferably a digital rectal one with disposable plastic probe covers... tympanic (ear) thermometers are trickier to use accurately and more expensive. See temperature, fever
suction bulb - used to suction mucous and milk out of the nasal passages or to clear the throat. Keep the one from the hospital - it works a lot better than the ones sold in stores. See colds.
saline drops - used with the bulb to wash sticky crud out of the nasal passages. The preferred decongestant for the very young
a can of Pedialyte® or similar electrolyte solution to have on hand for treatment of diarrhea or vomiting - it will save a midnight trip to the store - but certainly call your doctor for instructions about these symptoms especially in the very young infant (let's say under four months) See gastroenteritis

Older children add:

fever and pain medication - acetaminophen or ibuprofen liquids or tablets
diphenhydramine - Benadryl® and a zillion generics - for allergies, hives, beestings, and mild sedation
butterfly bandages - perhaps you'll get away without stitches
1% hydrocortisone cream - Cortaid®, Cortizone-10® - for rashes, stings, bites. Never put it on chickenpox.

See, that wasn't all that much, was it?