I am not exactly starting, but... my 5K is in 3 weeks. I had been training quite consistently until this last week when I was in a rope access class and it just killed my thighs all week long - to the point I almost couldn't walk! But today I felt much better and went for a 2.5 mile run.
My goal is to finish in under 30 minutes, and then continue training for a 10K in June. I'm finding that signing up for (and pre-paying!) races really keeps me focused on training.