Keeping your skills sharp is smart. Even if you have help (like me!) 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 image labels for a show. True story. Why on earth my client didn't ask me to do it I'll never know. Would have cost them, like, 25 bucks of my time. Go figure. But if you must do it yourself (and pay the opportunity cost), 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, go online and search for tutorials (hint: big time suck), get some of those Video Professor DVD's (I've used them, they work), or you can do what I do and learn everything from basics to advanced for just about any software on the planet by using the lynda.com video tutorials*. Why? They're the best, hands down. I keep an ongoing monthly subscription to their service so I can learn anything I want for less than the cost of one training book from the bookstore. They do a fantastic job, it's deductible (!), and it's really fun too.
Of course, after you update your skills the very best use of your time is to let me help you so you can get back to doing what you love and what makes you money.
I'm just sayin. ;-D
FTC Disclosure: If you know me at all you know that I don't recommend something unless I think it's absolutely stellar. All of the resources I recommend are my favorite things, and with some I am an "affiliate" which means that I will earn a small commission for referring you to the resources. Those are marked with an asterisk.