Yes you should get a professionl to write up a depreation schdule so you know how much you can claim each year,
And yes if you claim depreation you will be subject to more capital gains tax because if you purchased your property for $100,000 and then claim $1000 depreation your capital gain will be calculated on a purchase price of $99,000 ( correct me if I am Wrong)
So some people look at say that they don't want to claim depreation because they don't want to have to pay it back when they sell the property, How ever remember if you hold your property longer than 1 year you get a 50% capital gains discount, so you only have to pay back 1/2 of it.
and also If some one gave you $10,000 Interest free and said pay me back in 5 years would you take, of course you would you can use the money to save interest on your loan, make improvements that increase your rental yeild, or buy some shares.