It’s easier to pick a lock than you think. Even little kids can pick a lock. So you need to make sure that your deadbolt isn't dead-easy to crack open. If you’re asking how long it takes, how much skill is needed, and what tools are needed to pick a lock then it depends on the particular deadbolt, it will be somewhere between trivial and moderately difficult. At some point, anyone who wants to get in will just move to the windows or other weak points.
In general, a professional Locksmith will be able to crack open any lock you have, because that's what they do all day. The reality though is that with the exception of high security locks like Medeco, it doesn't even take a professional to open them.
A deadbolt is more about resisting kicking open or using a credit card to slide in and raise the bolt. It's not so much about being harder to pick, as the lock mechanism in it is going to be extremely similar to a normal door handle lock.
Things that really matter in a normal (not a high-security lock) are how tight the tolerances are, and how many pins. For example, the 6 pin Kwikset Titans are quite a bit harder to pick than the 5 pin regular Kwiksets, and a Schlage 5 pin is harder than a Kwikset 5 pin. But they both are dramatically easier to pick than a Medeco which has additional features to make it much harder to pick.
Bump keys can make most traditional locks quite easy to open. And anyone who has time and space to drill can get in to pretty much anything. One thing you may want to consider is putting a high security lock on your house may advertise to thieves that you have something you particularly want to protect.
To prevent these from happening what you need to do is to keep the lock well lubricated. This helps some of the pins from becoming stuck at the shear line. Install the lock upside down, so the jaggy side of the key goes in facing down instead of up. Beyond getting a better lock (higher quality, more pins, higher security design), these may be alternatives for slowing someone down.