Actually, the question has to do with where to put to and not when using the infinitive form of any verb. Adam asks in particular about to not seek and not to take, but nearly any combination of infinitive and not would be possible.
English teachers sometimes say that one should never "split" an infinitive -- that is, put a word (typically an adverb) between the particle to and the verb form itself.
So, for example, instead of:
To boldly go where no man has gone before.
such a teacher would prefer:
To go boldly where no man has gone before.
It turns out that the real rule is a question of clarity and style and not grammar. It's not wrong either way, but if one construction makes your sentence more clear or more emphatic, then you can use it. In the above example, to boldly go seems more urgent and may convey exactly the right idea to others. But both examples are grammatically correct.
However, the form that does not "split" the infinitive is much more common in print, and using this form (not to be; to go boldly; not to take) will work in almost every circumstance.
Here are just a couple more examples so you can see both kinds of construction:
Our parents told us to drive safely, to not stay out too late.
My cousin visited for dinner but decided not to stay overnight.
It's very hard to not think about the future.
I try not to think about how hard I'll have to work.
