One or two social media tweeters/posters needed.

Looking for one or two people to handle 2 twitter accounts. Need some research but most posts would come from information generated by the organizations. There are two organizations that needs this support and we will either hire one person to do both, or two different people to handle each campaign.
What we need:
>>someone who can write tweets from a newsletter -- create tweets that lead back to the newsletter and the info in it
>>someone who can research proper articles for the organizations and tweet them

Time commitment: approximately 3 hours per week to schedule the tweets for the week.