Newbie Questions – Sorry!

So in December last year we completed on a house in NSW and paid $365k for it with a 5% deposit.  To cut a long story short I'm now living in QLD and renting the property without an agent to a friend at the discounted rate of $360p/w with no agent fees or contract.  I spent probably $50k in renovating the house in the 3 months before I moved out into the place I rent in QLD.  My questions are:

Do I need to have a formal rental contract to be able to claim the property as an investment and negative gear it?

I know I need to see an accountant/tax guy but what can I sensibly claim in the way of depreciation? All money was spent prior to me renting it (as I was intending on living there) and  it was built in 1980.

Do you guys have any tips for a newbie with an investment property that might save me losing loads of money!?

is there any recommended software that I can buy to help manage costs and calculate rates of return etc? I would like to work out how much I need to charge in rent to become cash flow positive and how much tax I should expect to get as a rebate at the end of the year.

sorry for all the questions, there is lots to think about!

steve