Please read the following
Forum Searching | Posting | The Basics: (Make sure you've read them before starting a new thread)
Forum Rules - http://forum.xda-developers.com/announcement.php?f=642
Forum Search - http://forum.xda-developers.com/search.php
Google Forum Search - http://forum.xda-developers.com/showthread.php?t=304582
Advanced Searching - http://wiki.xda-developers.com/index...lopers%20Forum
XDA "Mantra" - http://forum.xda-developers.com/show...9&postcount=45
Post What Where:
General - general technical discussion items, news, anything else that does not fit into the other fora categories.
Q&A (Questions and Answers) - all questions, irrespective of type, get posted in here whether they be theme related, accessory related, technical, etc.
Accessories - any items to do with components and/or accessories relating to your device.
Rom Development - only meant for very advanced technical discussion directly related to ROM development activity and the delivery of actual ROMs and ROM components ONLY. Nothing else goes in here.
Themes & Apps - anything to do directly with the development of themes and/or applications. Nothing else goes in here.
EDIT: BEFORE POSTING ANY THREAD IN THE DEVELOPMENT SECTION, PLEASE READ THE FOLLOWING:
If you have developed a ROM, or are working with others to do so, the development forum is somewhere to discuss and share ideas, post useful feedback and logs or crash dumps, and to discuss a common goal developers are trying to achieve.
It is NOT the place to post your question because it gets higher traffic, or because more experienced users frequent it. Doing this just annoys those who are working on the device, and drives them away. Developers don't want to wade through 20 threads of "Help me urgently" to find their threads for porting and fixing camera issues etc. Similarly, if a thread is designated as discussion for developers say, porting a camera fix, please do not post in there asking "When will it be ready?", "Can I flash this yet?" etc. This is both completely disrespectful to those working on the project (you evidently haven't read the important posts in the thread), and also is making it harder for developers to find comments from other developers or testers when required.
Similarly, don't make loads of "Thanks for your work here" posts in an active development thread. It's just as annoying to developers as asking when something will be ready. If a ROM is complete, then go ahead and thank the developer if you wish, but don't go into threads for devs only, and interrupt it to post "thanks". It's basically spamming, and is treated as such.
If you are posting in development, you should have read every sticky and notice there, and should be actively developing or helping in the development of something. Developing isn't installing a ROM, or using a tweak, it's creating a ROM or other hack or tweak. If you haven't read for several days before starting out on XDA, you are likely about to ask something already solved. I registered on XDA when I first wanted to post, and that was to join in a discussion on something. Sure, join up and ask a question, but read the information available in General and Q&A first, as your question will have been asked before. Search is your friend here, become familiar with it.
Regarding when to post in development if you are not actually developing something, there is one occasion where it's acceptable. If you find a leak of a new ROM, which isn't already posted, and you verify it's legitimacy via either running it, or based on the source you obtained it from, then this is assisting in development, and should be posted in development. If you want to ask when a leak will be available use search first, then if not already in discussion, open a thread in general or Q&A.
If you have a problem flashing a ROM, this is NOT related to development. It's up to you to determine if it is specific to a particular ROM, and post useful information in that developer's existing thread for the ROM. If it happens on more than one ROM, and isn't a known issue (remember you should read several times more words than you post), then find out what you are doing wrong. Check guides written by others, try to repeat the problem and see if it happens every time. Something needs to be reproducible to be fixed effectively.
Once you have identified what you need help with go to the device Q&A forum (general if device lacks one), and make a clear, informative thread that explains the issue, and what you have tried doing to fix it. Did you re-download the ROM? Did you ask a friend to flash it for you, to reduce chance of user error? What steps (exactly) did you follow? What errors did you see (exact wording)? Did you double check all the steps? Did you do a wipe or hard reset?
If you make a clear, concise, yet detailed post, you will find help forthcoming, and should get the problem sorted very quickly. If someone suggests you try something, report back on what happened, did it work etc. Then, next time someone has this issue and searches, they will find this and have a verified and tested solution.
So remember... before you start a thread in development, ask yourself what you are developing. If you can't answer, then stop, step away from the post button, and think about where you are posting. Would it be better in General or Q&A, or is some more time with your best friend, search, required?