Utilities Refers to the additional costs for heating, hot water and electricity. Incl. Means 'included' and is likely referring to the cost of utilities and/or television cable.
Condo Is short for 'condominium' which is a home that is usually attached at least on one side and has shared property. Typically condos have more than one floor and have a mandatory monthly fee that covers property maintenance (for example: to hire someone to mow the lawn in the summer, shovel the snow in the winter, etc.)
O.B.O Stands for 'Or Best Offer', meaning the price is somewhat negotiable and the best offer made to the landlord will be granted the place.
1/2 bath Means that there is no shower. Many apartments and homes will have one and a half bathrooms, meaning they have one full bathroom with a toilet, sink and tub/shower and another that only has a toilet and sink.
ASAP Means 'As Soon As Possible'
Semi Means that the house is attached to another house. Some people also call this a 'duplex'.
First and Last This means that in order to move in the landlord requires two full rent payments (the first and the last).
Req'd Means 'required' (must do)
Appliances Typically include fridge, stove, washer, dryer, etc. - It is always important to ask about these things, since they are not always included when you rent a place.
Furnished/Unfurnished Refers to things in the apartment or house. If couches, tables, chairs, desks and a bed are in the apartment, then it comes furnished.