Weekly Newsletters are great for general information, tips, etc.. Using information from each PSA's profile page you can hone in on strengths and weaknesses of each member, and in a tactful manner approach each person through ECard or Email and bring up the subject of concern or interest.
Be sure that you start and end each conversation on a positive note, and spotlight yourself as a support system and not a boss.
The best managers will be seen as a lifeline to the PSA.