Here's a few good articles by Eric Ries I ran across today on startups.

In A Hierarchy of Pitches, Eric talks about aligning your pitch with what stage your company is in. This is helpful analysis and acknowledges that companies are at--and get funding at--a variety of levels in their maturity. Eric gives ideas about what investor questions are relevant at each level and what slide you have to focus on. If you're getting questions that seem misaligned with where you think you're at, then you should re-evaluate something.

In Lean Startups vs Lean Companies Eric defines what it means to be a lean startup in a very helpful way:

I suggest [startups] define waste as "every activity that does not contribute to learning about customers." (aka "how you get to product/market fit.") This is why I find the concept of the Ideas-Code-Data feedback loop so helpful. Any activity that actively promotes us getting through each iteration (including the learning phase) faster, is value-creating. Everything else (including a lot of traditional "agile" or "lean" tactics) is waste.

That's clarity around the key idea of what it takes to make a startup work.