Chris -- I'll give my standard advice for newcomers, but first, here's a preamble.
What I call the genealogy 'industry' (i.e. the big subscription sites) are keen to lock users into their own ecosystems. Most allow you to create a tree online and attempt to make it easy for you to attach records from their site onto your tree there, so that you have to visit the site again and again (and keep an active subscription). They encourage users to search for people by name, in the guise of making it 'easier'. Because of this, I believe they encourage people in bad habits.
During an online presentation I viewed from the US National Archives, one of the archivists was giving advice to listeners who wanted to find their people in the records she was talking about. I think her advice is useful for anyone looking for people in any set of records. She invited us to think about a three-legged stool. If you have only one or two legs of the stool, you can't stand on it or it will tip over. If you have three legs, you have a stable place to stand.
The three legs of the stool are
name, a
timeframe or
date range, and a
location.
Taking a wider view, if you goal is broader than "can I find my person in this specific record set", it also helps to ask a specific research question -- in particular, what Dr. Thomas W. Jones has called a
productive research question -- as well as a knowledge of what records might hold the answer to those questions.
So my standard advice to newcomers is to learn about the websites
before you decide to sign up for them. If they have free videos to watch that show you how to use the website, watch them before you pay. If they have free collections you can search, practice searching with those records to understand how the search engine works and how it displays data to you. Sign up for any free e-newsletters so you can get tips, promotions, and news about free access periods. Familiarize yourself with the site, so that you know how to use Ancestry's Card Catalog or findmypast's A-Z list instead of just leaping in to search for a name. If you don't know how to browse digital images which aren't indexed yet, take classes or get someone with more experience to learn how.
Then start keeping some kind of research notebook. Make note of new record collections which are coming online and make a 'wishlist' of what you'd like to look at, based on your time+location evaluation from the 'three-legged stool' exercise.
Pretty soon you'll know which sites, if any, you want to get a subscription for (or use at your local library / family history center) because your wishlist will tell you.
What you don't want to do is what I did, when I was first starting out. I purchased a copy of Family Tree Maker (ugh) which came with a subscription to Ancestry. (I am in the US, so this was one of the US subscriptions.) I wasted most of the period of the free trial just learning how Ancestry worked. (I quickly came to my senses and after looking at several other programs, chose Family Historian).
One of my husband's lines came through Canada. Ancestry sent me a promotion telling me I could see all these exciting records from Canada if I got a World Subscription. I bit on the offer and signed up for the World Sub. I discovered pretty quickly that I couldn't find any records about the family I was looking for. Why? Because they were in Canada for a very short time, between 1841 and 1845, which is before Confederation. There was no nationwide or province-wide civil registration at that time, so there were no birth registrations to look for, and there were no border crossing records, because the US didn't start keeping them until about 50 years later. If I had thought about any of these things in advance, I would have known doing research to find my research subjects would take more work than simply searching Ancestry databases by name. I did have some UK research to do, mostly in England, but I had already found most of the England Census records I needed on another website, so apart from collecting some BT passenger lists, I quickly ran out of records to look for.
You needn't keep an ultra-detailed research log with spreadsheets or specialized logs if that's not your thing, but simply writing down a list of possible questions and a 'wishlist' of records and research tasks you want to do (and why you wanted to look for them) is a HUGE help. Writing down notes about your research process gives you an 'audit trail' you can go back to later and see your progress as a researcher.
For example: Perhaps as a new researcher you search with only one spelling of your surname. Eventually you discover that spelling used to be much more fluid than it is now, and you need to repeat your older searches with variants. Maybe you take a class and learn how to use wildcards. If you've kept notes about what you searched for the first time around, it's much easier to repeat those searches with the variants or to put your new search skills to use.
P.S. for a productive research question, consider the difference between asking "What is John Smith's birthdate?" and "When was John Smith born?" The latter question is more likely to yield *some* answer, which you can refine as your skills get better.
If you haven't used the FamilySearch Wiki, take a look at their articles on the
Research Process. If you're doing research in England. the
Strategic Research Logs for England have tips on how to search.
Record finders can also help you think about what you want to search for.
If you can get access at a local family history center, also consider trying
The Genealogist -- they have some clever tools that help the new user correlate information on the census with BMD indexes. They're a bit pricey, but sign up for their newsletter to get their feature articles. I used The Genealogist as my sample site in a demonstration of how to evaluate a site's contents without a subscription here:
Catch 22: how do you know if a data provider's sub will be valuable to you — before you subscribe?
Another site which gets overlooked is
GenGuide. This site doesn't have records -- it has guides which explain different record types and has links showing you where you can see the records.