I am working on buying some real estate in another state.
what type of properties are we talking about? are you going to be actively or passively participating in these activities?
What all can I write off? Am I able to write off any trips I take to go look at the property after I've purchased it?
Define "look at the property". Generally, to be deductible, travel must be ordinary and necessary... are you showing the property to tenants? buying things to make repairs/improvements to the property?
the IRS is generally pretty lenient as it relates to business travel, but be sure to maintain appropriate documentation of your trips, because a lot of people get inquiries about these things.
How much a year are you allowed to claim as improvements done or upgrades?
generally, the fair value of the improvements is what you would claim as improvements. improvements are capitalized and depreciated according to a schedule that is determined by the type of asset that you are purchasing and putting into use. (additions, new patio, better windows, AC system, etc).
repairs and maintenance however, are expensed immediately in the tax year that they occur. (fixing broken windows, new paint, etc).
ive never heard of any 'limit'
Am I able to write off depreciation or any losses?
you can deduct depreciation, yes.
passive losses deductions are limited to passive gains and the 'at-risk' loss limitation (the amount of money you have invested)
then there are casualty losses, which I'm too lazy to describe at the moment... but it's easy to google so there's that.
When I rent it out do I have to claim any money that is above and beyond the cost of my mortgage payment as income?
you must claim all rental revenue as income... the mortgage payments would reduce the bottom line for tax purposes.
e.g. you have 100,000 in rent revenue, and 50,000 mortage payment. you record 100,000 as revenue, and 50,000 as mortgage expense (not 50,000 as revenue and no expense).