Learning a new game, especially a roleplaying game can be daunting with a bunch of new rules, and a world that is all fleshed out. It can take the wind out of the sails pretty easy to think you have to read 400 pages to play a game.
So sure, I have 30 extra sourcebooks for extra equipment and character options, but that is probably worth keeping on the shelf until the new player is hooked and wants to dig in deeper.
Sometimes it is best to just get the game going and go from there. In one such case it turned into a fairly funny anecdote.
I had a group that was all new to playing Deadlands. I tried to contain my excitement that they were willing to play something other than Dungeons and Dragons so I kept the tagline simple by telling them that it is the Wild West with zombies and other monsters and weirdness, and that we'll learn as we play.
To keep things simple I had everyone just pick an archetype character that we could either modify or toss after the first session and started playing.
The first session was meant to be pretty simple and introduce the mechanics to them. They were on a train from Missouri to points out west. At one point the train was going to be robbed by some steam-car bandits so they could get a feel for combat, the train would be damaged and have to make an unscheduled stop which would introduce the hook for the adventure next session, but first I wanted them to get the idea of non-combat skill rolls while they got to know each other. There was the dark mysterious gunslinger, the Chinese martial artist/laundry worker, the reporter, and the saloon dancer. The saloon dancer quickly got a reputation for having a very large chest because every time her player mentioned an item she needed she pulled it out from between her breasts.
On the train there was a kid who was playing with a tin horse. He was an irritating little scamp who was more than his mom could handle and was running around the whole train asking questions and generally getting in the way. When the player conversation slowed, I notified the group that the boy was now crying, wailing, bereft of all hope that joy would ever enter his life again. He had lost his horse.
So the ever helpful players started looking for it. I explained how the skill rolls worked, and asked each player where they were looking. I had settled on a easy to moderate difficulty as the point was to show how the dice rolls worked. It didn't really matter WHERE they searched, just that they did it, and when one of them hit the target number they would be the one to find it.
Everyone picked a location, under a chair, in the baggage rack, the sleeper cabin, etc. and rolled the dice. Fail, fail, critical fail, fail. Any one of them should have easily accomplished the task but the dice were against them. So we tried again, the players stretched their brains a little thinking of other places to look and we rolled again. Again the dice were only coming up with 1s and 2s, and no one could find the blasted tin horse. Finally, the player the rather busty dancer in frustration said that she was checking her cleavage. Roll the dice and success! No one could figure out how it got there, but the roll had it.
We all had a good laugh and the gal playing made it part of a running joke for the rest of the adventure.