If you plan on tackling even the smallest jobs on your car, motorcycle, trailer, etc- then you need tools. Good tools! You dont need to spend a lot on every type of tool, in order to have a good collection of tools. You just need to be smart. Sometimes paying more, is just a waste of money.
Ratchets: you dont have to have 10 name-brand(snap-on, craftsman, mac, matco) ratchets, in order to be a 'real' mechanic. In fact most mechanics have ONE name brand ratchet in every size, as their go-to ratchet, and the rest are cheaper equivalents. Personally myself, I have 1 Husky 3/8in ratchet that i love. I have used it extensively for about 5 years now. I also have a bunch of no-name brand 3/8in & 1/4in. They all have worked, and worked well. I also have a breaker bar i purchased from Harbor Freight, and it too has worked very well on hard to break bolts and nuts. I cant tell you how much money i have saved, by NOT buying the so-called "major brands".
Ratchet Sizes: You will find ratchets offered in various "sizes". This doesn't really mean, the length of the handle. The number you will see (3/8in for example) is describing the anvil that will insert into the corresponding sockets. Sizes vary from 1/4, 3/8, 1/2, 3/4 to 1inch. Let me say this much: you will probably NEVER need 3/4, and 1inch ratchets & sockets. So lets not even discuss those numbers. Those are for guys who change tires on buses, tractors, and other large machinery. This leaves us with 1/4(which is a tiny size) 3/8(which is a "normal" size ratchet and socket) and 1/2 which is the size commonly used for impact sockets(more on impact sockets later).
I almost never used 1/4in ratchets & sockets, but that doesn't mean you shouldn't invest in some cheap 1/4in ratchets 7 sockets. These ratchets and sockets are not designed for hard to remove bolts, nuts, etc. These are tiny sockets used in tiny spaces. So you don't need to invest in expensive 1/4in tools.
My 3/8in ratchets and sockets get the most use. I use these ratchets and sockets for everything from oil changes, to brake pad replacement, to putting an office chair together. I would invest in decent Harbor Freight sockets (long, short, and maybe even impact). These should last you for the rest of your life. Long sockets are great for things like spark plugs, or bolts on long threaded rods. My 1/2in sockets don't get much use. the only one that really gets used and abused, is the lug nut socket. these sockets are great where the nut or bolt needs to be removed or installed with 75 foot pounds of torque or more. These will be used for axles, trailer hitches, etc. Basically these are for the 'rugged' jobs. Impact sockets: these are matte BLACK in color(not a shiny black). these are designed to be flexible enough so an impact wrench, that's beating on it loudly, doesn't cause the socket to fail and explode. These are great to own if you use an impact wrench, or are planning on owning one, someday. Believe me when i tell you, that day will be sooner than later. With the advent of cordless electric impact wrenches & ratchets, there is no longer the need for hoses, and loud air compressors. Today's impacts are stronger, lighter, and more durable than traditional air-tools. So don't discount the impact sockets, when you see them on sale.
Styles: 6point, 8 point, 12point
Look inside of a socket; that part that gets put onto the nut/bolt. does it look like a 6sides stop sign, or a star? Personally, me- i stay away from 8 & 12 point sockets. they are known to strip bolts, nuts, etc. They are fine if you are not applying a lot of torque upon the nut/bolt, but for heavens sake please be careful. Sometimes the item we are repairing has these types of nuts/bolts on them, and we are forced to use such sockets or wrenches, so user be ware!