Overwhelmed and Excited

[MethodKC]

I want to apologize up front my first post with be long winded and full of some questions and thoughts.
Like many people in their late 30's my love for collecting hit a peak in the early 90's. My father was one of the few people who kept their collections from their childhood and kept collecting. We spent hours going through his collection, going to shows and buying new cards. One of my fondest memories was my dad giving me Fisk rookie at a show and telling me to go sell or trade it and I can use the money for whatever I wanted there. On to the late 90's. I get married have kids early and loose interest in collecting. Now fast forward to 2017. My father is still alive and well but they are downsizing and he tells me he wants me to come pick up our large combined collection because its sitting in his house collecting dust and he wants someone to enjoy it. So here I am now with a huge sports and non sports collection going back to the early 50's and I am beyond overwhelmed. I never realized as a kid all the stuff he had and I am enjoying myself beyond belief going through it, but as I dig deeper and do more research I realize how much collecting has changed and trying to figure out what to keep what to sell and what to trade.

The cards...I know pretty much everything from the early 80's on is has no dollar value but man it has been fun going through some and remembering particular cards and how much I wanted them and what I did to get them. Half of collection is from this period and its probably 20k+ cards that someday I will go through and see if there are any of the few valuable one in there.

Vintage cards. There are an overwhelming amount of awesome cards from the late 50-s through the early 80's. Complete or almost complete Topps sets from 65 on (with a brief hiatus in 72-73 when my parents got married). Most of the 50's cards and early 60's cards arent in the best condition because my dad actually played with them but there are some great cards in there. 54 Red Heart Mantle, A few early Ted Williams Bowmans, Lots of other Mantles ( like most people his age he was his favorite player) Ryan rookie in good condition and a few Bench rookies as well. He has almost all the inserts from the 60's most in reasonably good condition. There are lots of non sports cards from the 50s and 60s as well. Topps Look and See, Presidents, Astronaughts, The Beatles, The Monkees, Freddy and Dreamers, Planet of the Apes, Garrisons Guerrillas and more. There are Post cards and Kahns Wieners cards uncut, Kellogs and just about every thing you could send off for from the 60s and 70s. There is so much memorabilia I havent even scratched the surface on. (Programs and Tickets and such)

Ok on to my questions. Where to start. My father has been a set builder at heart his whole life. He never worried about grades just raw cards. I want to finish a few sets. I am like 25 cards short of 59 I think and close to some others. Money is tight enough I dont think I can go tell my wife I am going to drop a bunch of cash to complete some card sets so I am going to use the massive amounts of doubles+ and oddball stuff to finance this.
Grading - Should I grade anything of value I am thinking about selling? Scanning - I see Scans as people put cards up. What is the best way to get this done? Recommended scanner?
Places to sell and buy? Besides forums like this is Ebay the best place to sell and buy some of the harder things to find?

I will stop here because I could go on blabbing about my excitement and feeling of being overwhelmed. Thanks for taking the time to read this and for any comments and answers

Adam