Here are our picks for the top local stories to start your day:

Retired pitcher Roger Clemens arrives at D.C. Superior Court Monday for the start of his perjury trial. (Susan Walsh/AP)

Gray says D.C. could gain 250,000 new residents in the next 20 years, and he wants the city to plan for it now. Under a far-reaching new sustainability plan, to be unveiled today, in two decades most people would use non-car transportation and many homes and apartment buildings would feature compost piles.

Are you a student in need of 40 more minutes of class each day? Head to Prince George’s County. Most middle-schoolers there will face that much additional time per day starting next year. School officials say they want the additional time to enrich student instruction, but it will also save $5 million per year in transportation costs.

Coming up on PostLocal:

Already having a bad week? Log on for ComPost Live at 11 a.m. and join Alexandra Petri as she gives you a chance to laugh or vent about the news of the day.

Eugene Robinson will offer his take on today’s political headlines starting at 1 p.m. Join in to rant and rave about his columns or the rest of the day’s news.