There are a few things you should consider in purchasing a vacation property. First, how are you going to take care of it while you are away? condos are good choices since there is little outside maintenance. but barring that, you would want to consider a good property management firm to keep an eye on the place. Second, will the place you are looking at allow rentals and if so, what are the terms? Most houses are not an issue, but condos usually have some restrictions around rentals. And third, make sure it has good rental characteristics, such as # of bedrooms/bathrooms for the type of tenant you want, close to amenities/attractions, etc.
In terms of actually buying the home, you should work with a buyer agent to help you sort through the properties and find something you want. Once you have, the agent will write up a purchase and sale offer, which will be submitted to the listing agent. Your buyer agent should give you an idea of what the property's market value is so you can pay a fair price for it. The listing agent will present the offer to the sellers, they may counter back with another offer, accept your offer or just say no thanks! the negotiation continues until either you reach an agreed price with the seller, or the negotiations fail and you walk away.
It is customary for earnest money to be delivered with the offer - depending on the price of the house it could be $500 or $1000 or more. the earnest money check is generally made out to the real estate agency. if the offer doesnt go through, you get your check back. if it is accepted, it will be put into an escrow account and held for you until closing.
there are a series of inspections you can opt to do after the offer is accepted - water, septic, building, etc.. you pay for those upfront. If you find something wrong during this stage, you can renegotiate the price or walk away.
at the closing, you sign LOTS of documents! Since you are not a maine resident, when you go to sell, your property may be subject to withholding. You will have to pay a transfer tax based on the value of the house. You would also pay any prorated items that the seller has already paid, like property taxes.
In terms of renting your property, you do get certain writeoffs but typically just against what you bring in for rent. the mortgage interest can be deducted on your schedule A, but the other expenses would offset your rental income. If you want to look up more information on rental properties, go to the IRS website and search for information on Schedule E. Of course, you should consult with a tax advisor for the most accurate information.
this is a quick overview.. hope it helps.. feel free to call me if you have questions.