Should you get a second cat? How do you know when you are ready? Better yet, how do you know if it is what your existing cat wants?
These are difficult questions and they are not easily answered. Some guidelines may include:
Try to take into account the sex, age, breed, and past experience of your cat and any cat that you plan bring home before making a commitment. Do they each have experience being with other cats?
If your pet has been with other cats and enjoys their company, likes to play and having a companion, that is a good sign.
If your cat was socialized early with other cats, raised with litter mates and experienced normal cat to cat interactions, they generally deal better with another cat.
For tips on introducing a second cat in your home, please read Introducing a New Cat Into Your Household.