Daily stretches - where to start?

I'd like to start doing regular stretches, either daily or 3-4 times a week, whatever is best. Do you have any beginner programs and tips to share?

I'd also like to incorporate a ~5 minute plank workout I found online. I think stretches should always been last, so I should start with the planks, right? Does doing 5 minutes of planks warrant a warm up before starting?