Frankie,
Giving people as many choices as they can to contact you is ideal.
If you don't have a business number, use Google Voice...it's free and as Linda mentioned calls can be routed to your cell or your home phone and no one will ever know. The only problem I have with Google Voice is that when marketing locally, which I rarely do, but I advertise locally, the GV number is long distance and not local.
However, I would include email, phone, social media sites, website url...offer as many ways as possible to have people contact you. Some people don't want to make a call while others may wish to simply connect on Facebook. People like and appreciate choices so give it to them!
There is a great
thread on business cards and design.
Here's a great
link to a Google Voice discussion.
Janine