Welcome! :-)
First of all; Welcome to the Sitecore Stack Exchange Beta :-)
These last couple of days has seen a massive influx of new people arriving. This is of course excellent and we are very happy for it, but it is also important that we highlight what the current expectations are of people participating.
What's this all about?
The site, for risk of stating the obvious, is about excellent questions and answers.
We are currently in the Beta stage - this means we are building content and defining what the site should be, once we invite the general public in.
We are currently in Open Beta. In this stage it is very important that everyone engages with the site, gets involved asking and answering questions, helps groom the site (see: What are community edits and what is their purpose?).
We have a set of rough guidelines. This is updated and debated often. Feel free to check it out and join the discussion. https://sitecore.meta.stackexchange.com/questions/tagged/community-guidelines
Your questions will get upvoted and downvoted, all in the pursuit of building the best site we can with the best content we can. Don't get upset if you receive a downvote. "It's not you - it's us" :-) This site is not run "top down" - it's a wholehearted community effort. So in essence it's run by you. And me. And everyone who wants to get involved.
So what do you need from me?
Involvement. At this stage. We needs lots of engaged users, and we simply cannot overstate how important this is during this Beta period.
The most direct route to involvement will come quite natural to you.
- Ask great questions
- Post great answers
To get you thinking along the lines of what we're aiming for, here are a few tips and guidelines.
Poor questions
Ask yourself; "Is my question even a question?". It often is; but we're not really looking for "Hey, can Sitecore do custom fields?". Or "Has the bug reported in KB 4711 been fixed in Sitecore 8.1u3?". While they seem valid questions at first, they do not provide any long term value to the site. No one will come looking for that question a year from now; nor will anyone ever find the custom fields question ever again, once it leaves the front page.
Also; make sure the title of your question is actually meaningful. "Issue with Web Forms on Sitecore 8.1u2" is infinitely worse than "Index out of bounds exception when I use the Dropdown field type on Web Forms 1.4". "Sitecore Upload Window", "What goes wrong here?", "Will this work?" - all examples of perfectly horrible question titles.
Poor answers
For good answers; well. First and foremost they must answer the question. This seems obvious, but still needs to be pointed out. If you need further clarification to be able to answer, ask for it in a comment on the question.
Secondly, the answer must be contained in the answer. Almost Zen-like, isn't it? ;-) What this means is; we really dislike "link-only answers". Links go stale and forces our visitor to go someplace else to find (and deduce) the actual answer.
This is not to say, you should just blatantly copy in external material to your answer. You definitely shouldn't. But quoting your source in the answer and then providing a reference link is the accepted practice. If you add a dash of your personal expertise on top, with an explanation of why you believe your answer to be the right one - we're all set :-)
Also; while we're at it; make sure your answer is actually fulfilling. Not a direction. Don't go "You can solve that with field permissions" or "if you switch from Lucene to SOLR, your problem goes away". While the latter might be true - demonstrate, explain and argue why this is the case; preferably quoting references in the process.
Use embedded images when appropriate but also be careful you don't overdo it. Don't snapshot your entire desktop, when just a top corner of your Sitecore Desktop can exemplify what you are explaining.
What else do you need? How do I grow my reputation?
Besides asking great questions and great answers; the reputation system on the site is a marker for your active involvement in making the site better for all. The very best thing you can do, is to click your user icon in the top task bar and look at the "Badges" section.
The site will automatically chose a badge to "track" for you, and will tell you what you need to do to achieve it.
"But why?"
Don't think of it as a chore. Pursuing badges are completely optional. However; the activities covered by badges are exactly what we need right now. See a horrible title like the examples above? Edit them. See a question tagged with "SQL" but is really about "MongoDB"? Fix it. Help us with the housekeeping, and the reputation system will reward you for it. Real quick.
And don't forget to vote
Lastly; vote. Upvote great questions; upvote the best answers. See a question that you feel doesn't belong? Downvote it; later on you can outright start a vote to get it closed (again, reputation based). But do vote. Just - please - don't vote blindly. Only throw a vote if you well and truly believe it's a great question for this Sitecore Q&A site, and only upvote the answers that follow these guidelines; for detail and substance.
(it messes with our scoring and promotes the wrong kinds of content, if you upvote mediocre content)
Lastly
Have fun. Help us build this. Connect with 100s of Sitecore experts from around the world. We're happy to have you join us :-)