First, do what xanderwilson said. Then set up WPA on your base and your computer. When you're dealing with all Apple products, it's extremely simple.
When it comes time to choose a network password, don't use a phrase. While it's extremely unlikely that someone will try it on your network, it is theoretically possible to (eventually) break WPA encryption when the password is or contains dictionary words. Go online and search for "password generator." There are many online products that will generate a good one for you. Select a long one (25 characters or more), and choose all the complexity options: mixed case, numbers, punctuation, everything. Have the app generate several for you, and print them.
Now you'll have a printed copy of your passwords to put away with your financial records and other private stuff. But it will also let you use exactly the same password when you manually enter it in the base and the computer-VERY important stuff!
My final suggestion would be to get a router that supports MAC address filtering, and set it up to allow only your computer. All these things put together will make your network very secure, and none of them are hard to do.
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