cherrie Dreamer

Hi I'm new here. I have some coins that I inherited from my mom. all canadian. i did some quick research on the net and some are "proof-like" uncirculated sets (6-coins, different demonimations, sealed in those celophane wraps). In the same bag in which she kept these coins, there are also 11 LOOSE $1 silver coins (not wrapped in anything protective except an old fabric pencil case in which my mom kept the coins). but because these coins were not in a "special protective wrap" like the sets, the silver is darkened and discolored. while doing my quick search I saw that there are a few different kinds of these 1966 silver dollar coins (small, medium and large beaded) and depending on the type of beading, some of them can be worth quite a lot, even if they are circulated...(I have no idea how accurate is the website I found the info) anyhow, I am wondering, should I try to get some of the dirt off with a regular silver/jewellery cleaner/polisher? concerning some of the others, I saw on some sites they ask for authentication for the coins when selling them. is this truly necessary when they are sealed canada mint sets and if yes- where does one get such certs and what is the cost? Also where is the best place you can sell coins without getting ripped off? Thanks