Steps:

1. Decide with your spouse whether you want to exchange gifts or buy something together. Consider looking up the traditional gift for your anniversary year and buying something that relates; if you decide to buy something as a couple, exchange small tokens like cards or flowers.
2. Plan a quiet evening or getaway together. Many couples like to observe their anniversary in a private, intimate manner, especially early anniversaries. 3. Arrange a small party for your closer family and friends, if desired. If you decide to have a get-together, begin by inviting the bridal party from the wedding.
3. Plan a large party if celebrating a landmark anniversary, such as the 10th, 25th or 50th. Again, begin by inviting members of the wedding parties.
4. Consider reaffirming your wedding vows if you'd like to recreate your wedding, or have the large wedding you never had.

If you have a friend or loved one whose spouse has passed away, consider observing their anniversary by taking him or her out to dinner or sending a modest floral arrangement with an appropriate note of affection. Avoid mentioning the deceased spouse or the anniversary, and don't send an anniversary card to a widow or widower.

Set an e-mail reminder or devise some other method to keep you from forgetting your anniversary. Keep in mind that these are simply guidelines. Celebrate your anniversary any way you want.

Warnings: Don't expect your friends and family to remember your anniversary. In fact, it may be better if they don't.

Source: How to Celebrate a Wedding Anniversary from eHow.com - Clear Instructions on How To Do (just about) Everything