Now that you have your diary all set up you need to decide how and when you are going to update it. Some online diarists update every day, some more than once a day. Others once a week and still others only when they feel like it.
If you update less than once a week your readers will become very disinterested and go away. If you update daily, or more, then they may check on your site constantly and hang on your every word.
After you decide how often you want to update your diary you need to decide whether you will keep your entries all on one page or all on separate pages. You will also have to decide how often you will archive those entries.
If you write all your entries on the same page, that page will get very long if you don't put them on a weekly or monthly page once in a while. If you write all your entries on separate pages then you should created a special page each month to link to all your entries from the previous month.
When you create these archive pages it would be beneficial for you to link to the previous month and the next month from the top of the page so people can get around to your other entries easier. This just makes for a better user experience, the happier your readers are with your site the more they will stick around, read more and come back some other time.
How you archive will depend on how often you update. If you update your site once a week then you may only need to archive once or twice a year. If you update daily then you should archive monthly or even weekly.