You have some good autographs but the most important issue in autographs is their authenticity. It's nearly impossible to sell any any autograph without it being validated and the costs to do that are substantial. If you had each autograph INDIVIDUALLY validated it would set you back a lot more than you think. The two most respected authentication services are probably PSA or JSA.
So the best bet is to validate the autographs as a collection. In those instances where all the autographs were say on a baseball, the services often will validate all the autographs included on the ball and charge you the cost of validating the highest value autograph for the price of validating all autographs. So, you have 15 baseball autographs and the most expensive autograph to validate individually is probably Jackie Robinson. I would assume the cost to authenticate Jackie is probably around $125-$175. Same approach for football.
The real issue you have is for the display of the collection. If they were all on a group photo or baseball they would bring more value as opposed to simply being on a blank piece of paper or as part of a program. Just matting and framing a piece of paper with the autos is OK but less desirable for resale. The Dean, Jackie, Mantle, and Joe D autos are your best. Mantle and DiMaggio signed a TON but Dean and Jackie certainly will have interest when validated.
If you live near Philly, JSA sets up at the shows in King of Prussia. You can take your item and they will validate it, but they will probably take it with them although they will give you a tentative opinion within a couple of hours at times. They then send your item back with a typed letter detailing their findings. Ask them to give you a quote as a collection and ask for a discount. As an example I had a postcard set of 44 cards with 28 autographed. The highest value auto was Mantle which was $100 just for the Mantle. They certified all 28 cards for the cost of the Mantle cert of $100 and they gave me 10% disc. If they certified each individual, it prob would have cost me $500+ easily.