I used to run a will-drafting company, so you might expect me to tell you to use a professional but, as long as your wills are simple (not involving the distribution of agricultural property or the setting up of complex trusts, for example) there's absolutely no reason why you shouldn't do it yourself.
This book will tell you everything you need to know:
http://www.amazon.co....qid=1297808017&sr=8-1
(It's available in most public libraries, so you might not need to buy it).
The key thing to remember is that your witnesses must not be beneficiaries of your wills. Further, they must actually see you sign your wills. (If you sign your will and then take it round to your friend's house for them to sign, it won't be valid because they must witness you actually signing the will).
Further, your will should state what should happen if you and your husband die at the same time (e.g. in a car crash) or within a short period of each other. (It would be usual for you to leave your estate, or part of, to your husband only upon condition that he survives you for a specified period. Your will should then state what should happen to your estate if he doesn't).
Even if you do decide to use a solicitor (or another professional will-writer), I strongly recommend drafting your own will to start with, and then simply getting the 'expert' to tidy it up for you. Doing it that way gives you more time to consider all of the possible 'what if?' scenarios than if you were rushed into providing answers in a solicitor's office. Further, if the solicitor charges by the hour, it might also be cheaper that way!
Chris