I have an idea for a software product, I (think I) know how I'll sell it. I also know what will be needed to develop it but I have just a part of the technical experience needed, not enough to make if from scratch. Theoretically, the product can be built by a single person.
What should I do? Should I hire someone? Should I look for partners?
Well, ideally, if you can afford to hire someone it's better than taking on a partner who'll want a big chunk of your company. If you cannot afford to pay someone, you'd have to "give half" of your future company to a co-founder who'll do the development work you can't do.
Start by answering this question: can I afford to pay someone $30 - $60 an hour to work for me, considering the level of effort required.
Entrepreneurs / founders in this position should begin by first running the idea past members of your target market - thinking that you have a good idea for a product is a sample size of 1, which is definitely not enough to know whether there is demand or not. If you get good feedback from 30 - 50 members of your target market, then you have enough evidence to build an MVP, do more testing, iterate, etc, etc.
Pick up a more simple idea, completely unrelated to your current one. Then, do it. As its much more simple, you'll be able to finish it soon, maybe even able to finish it alone.
After that, pick up a more complex one, then another more complex, and another, another, until you reach the complexity level of yours original idea. In this moment, you'll notice that when you implemented so many ideas, you got a lot of experience, resources and contacts. The necessary tools to implement your original one.
My recommendation is the following: Make as much as you can of that idea without the technical person, create the wireframes, how each part should work, utilize software like protoshare or omnigraffle ro create a working prototype.
After you have done this you will have a better idea of what you need and have. From this point if it is a sound idea you can pitch it to friends and family and get seed money.
Use the seed money to hire this programmer and in the meantike handle everything else that needs work.
I hope this gives you some perspective and another way of getting things done!