Laws don't update often, unlike software, but we do see some of them update for many reasons. Let's say someone asked questions here, or someone visited this site, found a pretty good answers with certain laws cited. Now as someone who is not a lawyer, but would like to keep themselves updated with some specific laws. So they would be better informed with new laws in place. Is there some kinds of service where people can subscribe to for free? Thank you.
Laws don't update often
Laws update more often than you think between new legislation, new regulations, and especially, new case law interpreting the statutes and the common law. As pertinent to any particular U.S. state, it probably updates at least several times a month, and often multiple times a week.
When I was a professional journalist covering a Colorado law beat (among others), some of my go to sources were for state law:
The Colorado Supreme Court's case announcements webpage (it updates most Mondays, or on Tuesdays when the Monday is a holiday).
The Colorado Court of Appeals case announcements webpage (it updates most Thursdays).
The Colorado General Assembly (i.e. state legislature's) webpage (it updates every time new action is taken on a state legislative bill).
Most U.S. states have similar online resources. In addition for federal law I reviewed:
The 10th Circuit Court of Appeals case announcement webpage.
SCOTUS blog which provides comprehensive coverage of the proceedings of the U.S. Supreme Court, and
The How Appealing blog which aggregates news reports and scholarly work and original sources about appellate case law developments.
I relied to a lesser extent Govtrac which provides tracking of the status of bills in the U.S. Congress and mainstream news media sources such as the New York Times, Washington Post, and Denver Post, to alert me to new developments that I would then research and report upon myself from original sources.
I also regularly skimmed posts on the Law Professor's Blog network and a few other prominent law blogs such as Above the Law, Eric Goldman's Technology and Marketing Blog, Lawfare (on national security related law), the Legal Theory Blog (on recent law review articles), Professor Bainbridge (on the law of publicly held companies and securities law), and the Volokh Conspiracy (an academically oriented law blog with a libertarian slant, including a weekly roundup of notable federal appellate court decisions).
I also read the Colorado Lawyer magazine which is the monthly newsletter of the Colorado Bar Association and contains substantive posts about new developments pertinent to Colorado lawyers.
I also receive newsletters from various thinking tanks and interest groups, such as the Colorado Criminal Justice Reform Coalition. These newsletters track developments in the law in areas relevant to their subject-matter areas.
This strategy is all well and good when you have a position like the journalist's position that I had at the time, to follow literally everything that is going on in the law before deciding what to drill down and write about, but isn't a good strategy for keeping track of a specific field of law, for which paid services (for example, a subscription to the newsletters of the trade publication Law360) are more efficient.
I usually subscribe to one of the two main paid tax services, RIA or CCH, which provide updates on the changes in federal tax laws on a regular basis and provides pamphlets summing up new tax legislation when it is enacted.
Frequently, practicing lawyers will only research legal issues as they come up, and then resort to paid sources such as Westlaw and Lexis/Nexis to check the state of the law updated to the minute, at the time that the research question comes up.
Most lawyers are also required to take continuing legal education (CLE) classes on a regular basis, which usually contain updates on the law of the subject-matter of the class (with the specific subjects, other than professional ethics, usually left up to the lawyer in question).
Laws update, collectively, very frequently. Laws are embodied in statutes, regulations, and court rulings, statutes being the most stable of the three. In terms of what an individual lawyer would do, the most important is to focus on the relevant and ignore the irrelevant. If you mostly write wills and trusts, that defines a subset of issues that are important to you; if you are a tax attorney, that is another subset. If you ask a contract attorney about some highly speculative matter of constitutional law, the answer will most likely be "That's outside my area of specialization".
The concepts of "subscribe" and "free" are mostly antithetical. If you want the really good stuff, you can subscribe to Westlaw or Lexis Nexis. If you want the really free stuff (as generally seen here), the simplest solution is to use Google which may direct you to Findlaw, Justia, Cornell, Avvo or Law SE (unabashed plug).
New is not necessarily better, and frankly, new statutes are the least informative, because legislatures often say things that are less than clear on the face of it, and will need to await either administrative creation of a regulation that spells out what the law means, or a court ruling that does the same thing – maybe 10 years after the law was passed.