Keeping your computer skills sharp is important and a smart thing to do. Surprisingly, most people don't improve their computing skills over time, believing that they can "get by" with what they already know. The problem is, they pay dearly for it in lost time, money, and productivity.
Even if you have staff to take care of your computing needs, YOU still need to have good skills so you don't end up spending three days trying to print out address labels like a client of ours did. True story. Why on earth she didn't ask me to do it I'll never know. Three days of her time gone! It would have taken me about 30 minutes. Go figure.
So when you do it yourself, at least have the skills to do it in a reasonable amount of time.
No, you don't have to know everything but you should have a solid grasp of the basics. Take a computer class at a local college or learning center (or at the Apple store if you have a Mac), use the tutorials that come with your computer and software, or learn everything from basics to advanced by using the lynda.com video tutorials. Why? They're the best. They do a fantastic job, it's deductible (!), and it's really fun too.
I'm just sayin. ;-D