[Galaxy Tab S General] mitchellvii:
Experienced users already know this but we have lots of new people who come in ready to flash anything and everything. Here are a few pointers to keep yourself out of trouble:

1) You CAN break your new toy and turn it into a $500 paperweight. This is referred to as "bricking" your device. There are hard bricks and soft bricks. Soft bricks are recoverable with the right knowledge. This is usually something like a bootloop or being stuck at the Samsung splash screen. If your device will boot to atleast the Samsung splash screen or recovery but no further, you are most likely soft bricked. Be patient. Seek help and get it solved. Don't start just randomly trying things as you could turn that soft brick hard. A hard brick usually means you have a black screen and no further. Although this is not as easy to do as it used to be, it is still possible and royally sucks if it happens to you. (Guide to un-"soft bricking" your tablet - http://xdaforums.com/galaxy-tab-s/help/to-event-soft-brick-disaster-t2838473).

2) Check the firmware version being used by the developer against the proper firmware for your device. Make sure they match. If in doubt ask the developer. Some countries firmware are not compatible with other countries and can brick you.

3) There are 4 terms you want to know and understand - rom, kernel, recovery and firmware. Do your research and understand what these mean. Google is your friend. Don't ask the developer to explain them. This is your due diligence and your responsibility before joining the discussion.

4) If you are new please show some humility in the development thread. Give feedback ("this isn't working for me"), don't criticize ("this is rubbish!"), stay OT (on topic) and don't get into flame wars (playground arguments) with other users. If someone insults you report it and forget it. The mods will delete the offending comment and your ego will remain intact. If you simply must respond to the other user use private messaging. While the argument may be important to you no one else cares. And for gods sake, PLEASE read the OP (original post) thoroughly before asking questions. If the thread is well established there is a good chance your question has already been answered. Before asking do a keyword search. There are no stupid questions but repetitive ones annoy the locals.

5) Ask politely, never demand and NEVER be snarky or sarcastic. After you type your post reread it and ask yourself, could someone find this insulting? If the answer is yes, retype it. If someone helps you, hit the Thanks button.

6) Please, if you go into a thread for a Touchwiz rom, don't say, "wow, I wish this was CM", or "what we really need is AOSP". This is offensive to the developer and you are hijacking the thread. You wouldn't tell your girlfriend you'd rather be dating her sister - don't insinuate the developer's work is not good enough. If you want the developer to work on your behalf with a CM or AOSP rom, ask them directly in a private message so their thread doesn't get sidetracked.

7) Before flashing a new rom, ALWAYS do a Nandroid Backup of your current setup. That way if things go badly you can easily restore what you have. Don't be lazy. Do the Nandroid and give it a unique name so you know what it is later. These can be big. Clear out older ones once they are no longer useful.

8) In addition to a Nandroid backup do a full backup of your personal and system apps using a quality paid backup product like Titanium (don't be cheap, time is money and this will save you plenty). This will allow you to restore all of your apps with a click. In addition you can restore any system apps the dev may have "debloated" but which you still want. Remember, one man's bloat is another man's essential resource.

9) Be cautious, take your time and have a good experience. Roms can be awesome but they can also be trouble. Eyes wide open.

Thanks everybody :)