I typically use WWG terrain at 1" = 5', which is the D20 standard. Savage Worlds (which I use) is actually 1" = 2 yards, I think, but I like the 5' measurement more.
Most RPGs have movement rates for characters (ie, how far you can move in a given time frame) and some kind of round/turn sequence (ie, how long is each distinct time frame, from which also follows how much you can do on your turn to act in that time frame). You don't always use those; there are times when you're just purely RPGing (dialogue, downtime, etc) when it makes more sense to just generally talk about whats happening ("so the group spends the day travling towards the City of Glass..."). But when it becomes important (such as combat), you tyipcally "slow" the game down and break into your game system's round/turn intervals.
TAG is right - checking out demos are a good thing. If you have a little disposable income, a great resource is the D&D Basic Game Set (yes, I really said that). It comes with a very basic set of D&D rules, some prepainted plastic minis and some dungeon tiles, and is a good intro into gaming. You should easily be able to find that at any game store, and even in a lot of book stores (Borders, Barnes and Noble, etc), as well as Amazon.
And *ahem* I would also check out Savage Worlds.
It is a very streamlined game system that is quick and easy to learn, that focuses more on the action and less on the bookkeeping (which is a complaint you'll hear about the D&D system). They have a set of Test Drive rules at their website (look for the Downloads section): http://www.peginc.com/