Any competent developer should be able to show you a basic mock-up of what they're working on within the first week. It's not likely to be much more than a screenshot of a dialog someone drew in a dialog editor, a web page with no graphics but maybe a button or two, or even some interface sketches.

You should stop paying him if you ask him for some indication of progress and he flat-out refuses. Everyone works differently, with some people doing the visual eye-candy stuff last, but at the very least he should have some code written or some database tables created. You've paid for this code, so you own it as work for hire, which gives you every right to request a copy of the progress so far, even if it isn't working yet.

I would recommend asking any developer you hire to keep source code in a place where you can both see it so you can check on progress regularly. Something like a Subversion repository through assembla.com is inexpensive yet effective.

If the developer believes in keeping you in the dark that long he is either A) way out of date with respect to his/her development techniques or B) ripping you off. If he tells you that it just takes a long time to get a product "finished" then he's incompetent. What happens if he goes through the entire process - polishing and all - and you don't like it? You should be having meetings on a weekly or bi-monthly basis (at the most) to see if the system is evolving in ways that work for you.

Next time you look to hire someone, I'd suggest that you look for someone who employs Agile methods or, even better, is a member of the Agile Alliance. Frequent checks with the customer is one of the cornerstones of the Agile methodology.

By the way, I have been writing software for over twenty years and my company is a software vendor so this isn't theory to me.

If I'm working on backend programming, there is nothing for the non-tech owner to "see". However, that would go on for maybe 2 weeks at most and then I could show you the functioning, even if it didn't have a design layout for the user interface.

Also, when I bill someone I give them my day/hours with a description of what I did.

In this day and age no developer should go months without something to show. As a developer myself, I can tell you there's 8 million ways to mock up simple interfaces quickly, that while probably ugly and unfinished, can at least convey what the functionality will be like. I would demand to see 2 months worth of work or else you're going to get lawyers involved.

Don't let this sour you on developers though. There's unsavory people in every line of work, and this is no different. Just make sure to ask the developer to set milestones where they will give you a visual indication of progress at each one. Do yourself a favor and read up on agile development methodologies. You don't need to know how to program to grasp how the agile model works and how to make sure things like this aren't happening to you. If you can at least talk the talk, people will be less likely to screw you since they assume you know a thing or two about their profession.

You need to set up front what the expected milestones are for payment against progress of the project, as well as the nature of deliverable at each milestone. Without more detail, I'd suggest quarterly completion milestones (at 25/50/75/100% completion), or monthly progress submissions if the expectation is that you are paying monthly (although I would recommend bi-monthly at minimum, weekly is better).

This can be seeing progress against working application. Or it can just be submission to you of his source code / files / anything they've put effort into, so that he can be kept 'honest'. You may not be able to assess work, but you could have someone review to get a sense of how many hours when into the work, if you sensed a problem.

More frequent progress reports do more than make sure you are not being scammed, they ensure what is being developed is on track with your goals and specifications. This is often very important with web projects where specifications are often verbal or vague. I'd be very afraid to not see anything after two months -- the deliverable may not be what you expect, even when you do see something.

You need to reset your developers expectations immediately - he should turn in whatever he has done thus far to validate payments made to date. And have him suggest what the milestones going forward (timing/deliverable) will be, if you are not able to. If you don't like his answer, cut your losses and get another developer.