It all depends on how long you want it to be before you buy more. If you want to avoid becoming dependent on diapers for every tense situation, I suggest that you exercise strict self-control over yourself.
My current schedule is one diaper per week. That scales to doubling up on a weekend, then waiting a week and a half, and wearing during mid-week, then waiting another week and a half. It sounds limiting, but it's turned out to be "enough" for me and if this is your first package of diapers you'll probably find that once a week is fine.
When I bought my first pack I would take one diaper a week and wear it for an hour or two each night for a few days a week, then wet it until it leaked (which wasn't very long) on the weekend. That didn't work out very well because they were plastic-backed and thus the tapes could only refasten so many times.
Do what's best for you, but don't hoard them. You'll find yourself helplessly addicted it will be hard to stop if you try to wear 24/7, and you'll burn through probably 2 or 3 packages within the space of 2 weeks, after which you'll swear you'll never want to wear diapers again. This is called the binge-purge cycle and the effects can be limited if you are careful to space out your diaper-wearing days so that it's something you look forward to, rather than using way more than you can afford and then swearing off of them.
I'd post more but it's 3:30am and I'd best be getting to bed.
--Danny :ninja: