Help Base Set Collection Help!

[Grimalkin]

I have been holding onto a Base Set collection that I collected as a kid and put straight into a binder and had some questions.

1. What should I value this at?
2. Should I have any cards graded? If so, how does that process usually work?
3. What would be the best way to sell it if I decide to do so?

Here are pictures of the collection. The first couple of pages are duplicates, followed by a complete base set with some first edition.

 

[Grimalkin]

Here are the rest of the pictures.