We need to know if you have Geraniums (frost-hardy, blue/pink/white flowers) or Pelargoniums (frost-tender, red/pink/white pom-pom flowers). They are propagated in different ways.

They're Geraniums...I'm almost positive they're Martha Washington and since it's gotten hot, they've been growing and flowering like crazy so I thought it'd be nice to use some of the extra growth and replant in different parts of the garden.

OK, so they're Pelargoniums :) Martha Washingtons are called Regal Pelargoniums, as distinct from the less spectacular Zonal Pelargoniums.

Cuttings are very easy. I place them in water, they take 2-3 weeks to root, but it can be quicker if it is warm. Remove the lower leaves and any flower stalks first. Now is a good time to take cuttings.