Re: Perhaps basic questions - but your advice will be a huge help!
Changing switches and outlets is generally a pretty straight forward endeavor, though something you've said has me a bit concerned.
You've got 2 prong (ungrounded ) and three prong (grounded ) outlets. It is quite likely that the three prong isn't actually grounded, if that is the case, then you either need to reinstall a two prong OR install a GFCI.
The switches aren't all that difficult either if you pay strict attention to the location of the wires on the switch. Your wording indicates that these are either 3-way (two switches on a circuit ) or 4-way switches (three switches on the circuit. ), which increases the difficulty should you not place the wires properly to the new switch. Standard 2-way switches are easy-peasy to swap.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!