Best place to look to ID the year is the bottom bracket, there should be two numbers. One gives month, year and frame size, the other is the serial number. If the bike has a heart shaped cutout on the BB it was made in Mexico in the 1980's, and Benottos from this era are regarded as having weak frames due to overheating of the brazed areas in manufacture.
As to how much your bike is worth, that's an open ended question. Value is what someone is prepared to pay, so I would suggest doing an internet search to see what other people have paid for them in the past. It would also help you to try and identify the components and assess their condition. The model is low to mid end and not regarded as anything special (though the forks are apparently quite good) so I wouldn't get your hopes up.
Incidentally, there is a sticky thread for questions like this. It might help you if when you've done a bit more research you posted the question in there, probably get more answers.
Good luck and keep smiling