Registering with LSAC
LSAC runs virtually everything connected with applying to law school, and they name all of it with virtually identical acronyms.
For most people, the only two acronyms you need to know refer to the admissions test and the recommendation service. You'll need the LSDAS, but you won't need to call it that, since LSAC staff use the second half of the name ("Credential Assembly Service," "Candidate Referral Service") in most instances.
But regardless of whether you'll need one service or everything they offer, you MUST register with LSAC in order to apply to law school.
Opening your Account
You start at the LSAC home page. At the top right, you must tell them you're a J.D. candidate. Why? Because prelaw advisors and law school admissions officers log in through the same portal, but gain access to different information.
When you click on the Login button, you get taken to a page for people who have already registered — no surprise, most web pages do this. The "If you don't already have an account" button is a little less obvious, but it's there. Click on that link and begin creating your profile.
Along with the login button at the top right, there are many other important items that no one reads. Then when they get caught missing a deadline or breaking a rule, they say, "No one told me." Lawyers don't get told stuff; they read, analyze and implement. This is a great time to start learning that skill.
A Social Security number is NOT required to register for LSAC; however, it IS necessary to get financial aid, so you might as well enter it. If you don't,
Note also that you can check "multi-racial." I've been told by a few law schools that they don't like this; it makes it harder to match up applicants to federal reporting guidelines.
You fill out a lot of other stuff here; you create your user ID and password, add email addresses and phone numbers (note the plural there), and register for the "Candidate Referral Service" [CRS]. Anyone who IS applying to law school would be a fool not to register for this fabulous service! You'll get junk mail, sure, but you'll also get fee waivers, application requests, and a good sense of how high up you're marketable.
There are probably other things I can say here. The most important is: be honest, be careful, and be complete. This is where most law schools will get their first look at you; don't make them decide it's their last look.