So to me I would do this in a few steps , firstly I would guess how much time per day or eek you have to this project,
then sort the coins into countries and by value as on the coin,
consider the metal are they silver or some alloy like nickel /copper,
then look at the highest quality coins and find them online, use a notebook to keep track of info you find . . .
no coins will sell by their condition, popularity, denomination,
generally you might assume a french coin might have a higher value than a coin from middle africa , simply because their are more coin collectors to push up demand in franc than in central africa...
Once you get some idea of what you think are big ticket items then seek helpers online to gain some idea as to demand and value,
generally I think most average collections have a lot of cheap fillers that have just been acquired and some very nice /potentially valuable stuff ; sometimes that value might be in the tens or hundreds of dollars or even higher,
any quality image will do to give an image as to the state and type of coin like its quality overall. You may find some awesome looking coins and the image shows that type of coin is worth $8 only.
but you need some sort of feel for the overall collection and then you can decide if its worth paying to have it professionally appraised.
if all this sounds to much or your very busy or whatever you could simply offer it as a bulk sale or gift it to someone like a youngster.
Remember Rome as not built in a day, you might spend to years of spare time to nail down solid idea of its contents and value ! ! !
Just go slow and if you have the interest you ill find you get a lot of basic information on coins even in the first few weeks.
sure you will not be an expert but at last you ill know never try and clean coins, ho to handle them to prevent damage and ho to avoid a rip-off con artist eager to separate you from certain coins.
many coin lots are best sold as is intact rather than separately removing the best coins and then finding their is little of importance left to interest buyers...