Greg Mankiw's advice to new junior faculty at research universities:

Your focus should be on getting papers published in refereed journals. Everything else is secondary...

Avoid activities that will distract you from research. Whatever you do, do not start a blog. That will only establish your lack of seriousness as a scholar.

Remember that you got into academics in part for the intellectual freedom it allows. So pursue your passions. Do not be too strategic. Be wary of advice from old fogies like me.

When it comes to research and distractions therefrom, I (still a grad student) find that the negative method of focusing on research---not doing fun activity X---doesn't work very well. I just switch to fun activity Y. Producing new mathematics requires a positive desire on my part to do so. Such desire is most effective when it is most specific, e.g., "I just know that I generalize that criterion I called `Phi is empty' to prove that under Martin's Axiom there's an ultrafilter on omega that is Tukey equivalent to..." And now I must end this blog post, for I'm really curious about applying Jensen's Diamond Principle to...