The recs are from former members of each sorority (they are national sororities) which are submitted prior to recruitment for the sororities to review. Ask your parent’s friends, or anyone that knows you if they were in a sorority then note which one. If you don’t have contacts then ask the Panhellenic in your area - or if that doesn’t exist, ask the national chapter of each sorority for someone to contact to write you a rec. You will provide a resume which includes GPA, scores, activities & picture, the person writing has to normally answer some questions about you & give their okay that you meet the general guidelines of membership. The writer will submit it to the college directly.
You fill out an application for recruitment which goes to all the sororities from the Panhellenic office. Recruitment is a week long activity during howdy week - it a full time commitment that week. You go to all the houses day 1 & day 2. You meet a few members & they meet you. You sit & chat for a specified amount of time - don’t worry the sorority members are in charge of that part & they will ask you leading questions to keep the conversations going. Then you come back and rank the houses you visited for your favorites & they do the same for those they would most like to see back for potential membership. It is rounds of this that occur and each round you go to fewer and fewer houses until the last day (preference night), Then you rank the last time, and you are matched with your sorority. Bid day is the following morning & you get envelopes that invite you to be a member of a sorority.
Each day along the way has a theme and specific attire to wear. You are given a guide by panhellenic that shows you what to wear ( ie. shorts & sandals with a provided tshirt, formal dress with heels, etc). The girls in the sororities also have specific things to wear (it makes it easy to remember which house is which) and specific songs/chants to welcome you into the house and a good bye song when you leave. There are rules as to what they can and can’t say to you ( eg. we will be offering you a membership bid is NOT allowed). Some girls get invited back to every house they go to and have to cut their lists, others do not get invited back - that is the brutal part. You need to go into recruitment with an open mind vs. a preconceived notion as to which house you want - that often does not work out. Practice talking to people you don’t know at various events and parties prior to attending recruitment - it is a skill and one that serves you well in the long run anyhow.
Now that I’ve gone through formal recruitment, there are also non-national sororities on campus. They do not do formal recruitment, they are much easier to join. My D was in a national sorority, her best friend was in a local one. They both had wonderful times. The local ones are less of a formal commitment, they do not have houses but do many of the same types of activities on a smaller scale. They start their process of recruitment after school starts in the fall - easy going social events, no special attire needed more like mixers. They are much smaller in size - a national sorority here has about 200 members, a local one might have 30. Go to the Reed arena event that advertises all the clubs and organizations shortly after school starts for more information on all of those groups.