I have several ideas that I wonder if they would be good enough for filing a patent. I dont' have prototypes since the ideas are new. Would it be best to ask in context at a specialised site for that technology e.g. if I'm asking about if a software idea could be a patent, where should I ask? Sppecifically I had an idea for a new kind of software for a telephone switch using queue theory from management science.
The quick answer is that Ask Patents probably isn't the right place for that question.
I can point you to our scope page for the details, but essentially, Ask Patents is for questions about the patent process, and not the underlying technologies behind patents--yours or others you come across. You could theoretically ask something along the lines of "could I get a patent on this?" but in reality, the answer to that is "it depends on what the examiner has to say about it." So most questions like that turn a bit too opinion-based to be constructive.
You might find luck on other Stack Exchange sites, and I'll gladly help point you in the direction that I think would best-suit your question, but first, a word of caution. I'm a bit unclear on what exactly you're hoping to ask, but whatever it is, note that the patent system (United States or otherwise) gets a lot less helpful after you make a public disclosure. If you tell people enough details about your invention, your rights can be substantially decreased. So do be careful if the question you're planning to ask is enabling.
An often-safer bet is to bring your invention to a patent professional. That can be a patent attorney or a patent agent, there's not a lot of difference for this particular task. But they often have the technical knowledge to help you decide whether an invention is worth patenting, and they can help guide you at least to understand the advantages and disadvantages of it, as well as the cost associated.
Honestly, I'd be tempted to speak with a patent professional before even trying to ask something anywhere on Stack Exchange that's specific to your potentially-patentable invention.
If you do still want to ask, I'll gladly help you find an appropriate site, though, but I will need to know a bit more about what your specific question is.