How to correctly evaluate and sell the painting?

[Obstler]

Good day to all participants.
Go tell that I have nothing to do with art, and even more so am not an expert in what either direction.
Break the entire forum, and the entire 'Net in general, specific information seems to be much, but more or less comprehensible to me personally the answer to your question, I could not find, so try all the same to formulate and ask questions.
Introduction.
There is a picture, presumably Lagorio (this is a signature), the size of approximately 110h71, acquired by an ancestor in an antique shop in the Soviet times, was inherited by, the documents at her no, information, too.
City of Moscow.
Problem - the most profitable to sell this very picture, date of sale is practically unlimited, effort and money ready to spend - T e, for half the price "just to get rid of" do not give.
Now the question - what should be the algorithm of Action for the unenlightened man, who, in his completion of the maximum possible number of banknotes?
As I understand it, the order of approximately the following:

- Preliminary assessment.
- Examination of authenticity.
- Thin. examination.
- Search for a buyer and sale.

Where to go, where to call, where to drive it, who to trust - who do not like to sell through the auction, which auction to choose and how to do this?
I hope to help, are interested in any information.
Thank you.