not magnetic would mean they are silver. As for getting graded, I'm not sure it's worth it. Unfortunately, the silver version of these coins are easier to find in higher grades, and sell for less. I'm guessing because people kept them once they found them since the composition was nickel from that point on. FOr the 1968 quarter, it would be a MS65 at most, and even then it would sell maybe for $20-25. I paid $35 once for one because it had a nice cameo. But for the dime, if it is a business strike, could be a MS66. Those fields are really nice and clean. And you've got a nice cameo as well. On
ebay, one of these sold for $30 in auction. If you put it as buy it now and wait for it, you could probably get $50 in my opinion. So I'm not sure if you want to get it graded. Before doing so, get some more opinions here on the forum.
As for your questions
1) Is it worth getting graded? Both of the coins or just something like the dime.
Maybe the dime. The quarter, not really.
2) Where do you go to get it graded? What's the best way to go about that?
ICCS would probably be your best call. They're located in Toronto. But for it to be worth it, you'd want to amass a larger number of coins that are worth grading, and sending them all in at once. Presently, I think one coin will cost you $16 to get it graded, plus taxes and shipping. So not worth it to send alone. But once you send in 6 or more, $11 each, then 50 or more, $8 each, and I think at 100+ it caps at $6 each.
3) How does it qualify to be PL.
ProofLike coins for this date came from PL sets. These were made to be collected. They tend to have nicer, more defined rims and squared lettering. The strike is just nicer overall. But like Alan said, this is probably a business strike