This is kind of funny, because based on how people pronounce this, you can tell whether they're from Bohemia or from Moravia. Moravians pronounce the first "s" as if it were a "z" and then they simply pronounce the "ch" as "h" (the way "h" is pronounced in "hand"). Bohemians pronounce it with an "s" and then with a "ch" sound which is not very common in English, but in German for example in the word "machen" it is pronounced like that.
And some people actually do say "naskledanou", pronouncing the "ch" like "k". It might also be regional though.
If you want to use the standard pronunciation then the Bohemian version with the "ch" like in "machen" is probably the one but Moravians might disagree :-)
You mean the literal translation? The closest to a literal translation would be "to meeting!" (with "to" in the same sense as if you wanted to make a toast). But it translates as "goodbye". Another way of saying that is "sbohem" which literally means "with God - s Bohem". But you only use that if you don't expect or want to see someone again and it would be rude to say it to someone otherwise. Kind of like "farewell" in English.
With friends you usually say "čau", like in Portuguese "tchau" (and almost the same as in Italian) or also "čus", which comes from the German "Tschuss/Tschüss"). You can also say "ahoj" for both "hello" and "goodbye", but again this is used among friends or people you know well. With strangers you usually say "dobrý den", i.e. "good day" and "na shledanou", i.e. "goodbye".