1. How do I find someone that can help me with my idea?
2. How do I make sure that they are really capable of doing what I am asking them to do?
3. How do I ensure that they don't just take my idea and run with it?
4. If someone is found, how are these sorts of partnerships usually split monetarily?
2. Review previous work, ask friends who are technical to review his/her previous work.
3. You could do a non-compete, but would be expensive to enforce. So really, you can't. But if he can just take your idea and execute it better, why can't competitors anyway?
4. Depends (are you funded? is there a salary involved?), but I'd suggest just 50/50.
1. Universities often have good coders willing to work part-time (but you may have to pay). Also, try the HN co-founder spreadsheet: http://docs.google.com/leaf?id=0AgCvDTyBjHdOdDFfMENqeWVGNVFx... =name&layout=list&num=50
2. If you're not technical, you're fucked. You can't really know. If they like math or know (relatively) obscure languages like Python and Haskell, you're in luck. This is one of the hardest obstacles you'll face (with other being if they have your level of passion and commitment to the project.)
3. You can't; don't try. Creating something compelling is not about programming it. It's a thousand things and most of them are conceived/created as you're doing it. In other words, at the beginning there's almost nothing to steal, despite how it feels.
4. A good technical co-founder is worth their weight in uranium. Those that have doubted this are those that have had to learn the hard way. If you go 50/50, be prepared to do a ton of work in bus. dev. to compensate.