I'll be starting a "startup" that will require me to see existing code, propritary data, etc. I'm sure that most of my potential clients will not already have an NDA for me to sign so I want to be ready with one. What elements does the NDA need to have? I'd like one that doesn't require modification (or at least a lot of modification). I also have sub contractors that would be doing work. How would that affect the agreement?
An NDA is pretty basic if you just want to cover the minimum (which for any client who isn't providing their own is likely all you need anyhow). Specific circumstances might require something more, but searching online for a template and making some small edits will probably cover you.
The document needs to say:
In regard to sub-contractors, your probably best off having them sign an NDA with your company, and then another for any client who requests it. Better safe than sorry.
not sure Im answering your question precisely as you've bullet pointed, or that Im qualified to do so but .. I found the following resource very useful in crafting my own NDAs, they have template ones that are very useful and are free http://www.wipo.int/sme/en/documents/disclosing_inf.htm The larger the organisation you deal with, the more likely they'll have their own NDAs for you to sign.
Generally though, I have a rule of not sharing anything with anyone who is even slightly at risk of breaching confidentiality.
I use a few standard NDA's but am always finding that I need to modify it to make sure I cover all aspects of the business deal that may transpire.