Being a member of many SE sites, the first place I go is the Tour. E.g. I recently joined Lifehacks, so I read the Lifehacks Tour.
However, once you know one SE site, you'll find that the relevant information is just in one section called "Get answers to practical, detailed questions". This section differs between sites and defines the scope.
Ok, I read that part carefully, and scrolled on to get the "Informed" badge, not for badge hunting reasons but to remind myself that I have read the Tour.
Next, I asked my first question, which seemed on-topic for me, but it was put on hold by a moderator later. That's frustrating. I put a question on Mate.Lifehacks why it is not on-topic for the reason I thought.
I put this on Meta.SE because I had similar issues on one or two other sites, so this is a Meta problem and not a Lifehacks problem.
The Tour IMHO performs really bad when it comes to defining the scope. There are only 4 statements (more or less) on defining the on-topic stuff and usually not even specific reasons for what is off-topic (Lifehacks is pretty unique in that case BTW).
There is no link to anything else that could help someone learn more about the scope.
What can be improved?
For first time users, leave the page as is. They need to learn how to upvote, downvote and accept answers. That's ok.
For multi-site users *), remove the fluffy upvote/downvote stuff and boil it down to relevant things, i.e. only the "Ask about... / Don't ask about ..." section
For multi-site users *), add 4 to 7 links to the most important Meta questions defining the scope of the site. This could be some highly upvoted scope questions or something the moderators define as useful.
*) We probably want to make sure they have at least one "Informed" badge or other indicators that they know how to use the voting system, e.g. we might want to change the Tour appearance only for those who have received the site-association bonus.