I am a CS Major and planning to transfer to another university. I wanted to know whether volunteering or ask my professor if I could become a Teaching Assistant would aid in my transfer application in any way (Maybe a better recommendation letter from the teacher or if it shows mastery of a subject in the application)
Being a TA would help, though you need to check up on the requirements on becoming a TA/LA. Some universities do not permit students to TA/LA until they have completed a certain level of the subject (eg. TAing/LAing a General Chemistry I Class and/or Lab may require you to do well in BOTH General Chemistry I & II.)