Since being away from the technology, what are some of the best practices of today? Backend, front end. php, asp, off the shelf dev tools?

If I was just starting out, I'd consider learning Meteor (https://www.meteor.com/). It's just entered version 1.0 and after working with it for a little less than a year I do have some issues with it but it still makes for a very solid framework that gets you up and running very fast. You would only need to learn Javascript, and you can slowly work your way towards nodejs from there (which Meteor is based on) if you want to, or you could get the basics down and focus on learning design if you prefer.

Create an ideal customer profile. Create some questions that will allow to you survey a potential tester to determine if they fit your profile. Design simple landing page with very clear value proposition that speaks to your ideal customer. Ask for a minimum of information up-front (email), but ask for more info after they commit by submitting the first piece of info. (KISSmetrics does a good job of this on their current website trial signup). Use the their answers to these profiling questions to put the applicants into buckets. Let in the most ideal bucket first, or split them into groups if they're big enough. Try and measure engagement the best you can. Measure qualitative and quantitative data. Schedule calls with your beta testers to find out more, especially with the ones who's user behavior seemed to indicate that they didn't get value from your product. Find out why. Make sure they are indeed your ideal customer. Pick up the phone and get to know your customers inside and out. Meet them in person if possible. Incorporate their feedback quickly and get more feedback. Rinse repeat.

I hope this answer will help you in two ways: It should help avoid unnecessary expense being incurred and it should also help you recruit software engineers to build your project. Before you spend a single dime on building, I'd encourage you to validate the idea itself with potential customers. Identify the kind of person you are thinking of solving a problem for, and just explain the high-level concept. Make sure that a sufficient percentage of them are saying "yes, I need this." Then, really distill the idea further into a single piece of functionality that this customer base says they want. There are tools that allow for "drag & drop prototyping" like fluid.io that you can use to create a clickable walkthrough of the user flow you're looking to create. The more that you can do to validate the idea and focus it, the more you can define your "Minimum Viable Product." If you can't find enough of your potential customers to get excited about the idea, I would advise against hiring anyone to implement anything. That said, it's also a lot easier to recruit talent when you can say "I spoke to 100 potential customers and 40 of them said they would use this" or better yet, pay for it. Convincing anyone to work on your idea will be considerably easier if you can show some existing proof or interest around the idea. From there, your best source (assuming you don't have a network of people to draw from) might be local colleges & universities. I would advise against hiring online or working virtually with someone when you are new to building product. I'd be happy to talk to you about your project, how to validate the concept and how - if you decide to pursue it - to hire good talent. Best of luck!

I recommend that you get technical cofounder as soon as possible. Using a contract developer to create a prototype is ok but keep in mind that startups need to iterate and be very flexible in the early stages of company/product development. A contract developer works best on a fixed spec and will be hard to adapt without a lot of extra costs and frustration on both sides. Go get a tech cofounder, somebody invested in your product and willing to be flexible and adapt as you discover what your product really is.

If you are aiming on iOS and Android with Windows Phone 7/8 as a plus you should use C# as the language and Xamarin Studio as the IDE/Framework. You may also choose to use Visual Studio on Windows as an option. Take a look on their website: http://www.xamarin.com Even Microsoft is using Xamarin to build iOS applications and they have over 400k developers using it. Your application will be native (compiled to the platform you choose) and you are able to use all the native libraries, widgets and UI parts. You will need a cross-platform architecture to be able to reuse code among platforms and using Xamarin you may be able to reuse more than 50-60% of your C# code among platforms. This solution may render the same experience on the devices as on the website, but it enables your applications to deliver much more performance and features than any HTML5 solution. Facebook went from HTML5 to native applications due to performance and user experience limitations (gestures and other platform features are not present using HTML5).