Why have someone in your business to reap some of your profits? From what you wrote, it sounds like you need another pair of hands more than a business partner. Outsource your financials to an accountant/bookkeeper or an admin person to do the financials AND run the "office". Just reading the job ad on Seek or mycareer will give you an idea of what some businesses expect their admin person to do nowadays - a jack of all trades.
Unless it's someone who can for example open up or expand your market (say export) for you, have lots of contacts and they want to be partnered in your business then a partnership may be called for.
Some links on partnership on this forum that may be helpful:
Partnership Agreement? Partnerships
There is another thread that I can't find where the partnership has gone sour which is worth a read too.
Good luck!
KoB
www.mygoodolddog.com