OK, so you have a machine. It does NOT have to be a super flash thing that does everything except wear the damned clothes - my current one is cheap and cheerful and absolutely super. Price-wise - this cost me about £140 about 4 years ago, they are available cheaper and simple ones like this also sell second hand. Ask around, you might be surprised who has one sitting unwanted and unloved upstairs - borrow one or two, and see what you like. Is it quiet enough? Smooth enough? Easy to thread? Does it seem strong enough for your needs - this little machine wouldn't be too happy about sewing a lot of thick heavy denim for example. Find a decent sewing machine shop and don't be afraid to ask! Do not be led into the expensive side - machines can cost thousands.
This (above) is the side of my machine - the little switch is the on / off (I warned you this was going to be literally step by step! don't be offended!),the light on this one comes on automatically when I flick the switch, on some models there is a separate switch near the light- the black connector leads to the plug, and one wire leads to the foot pedal which is under the table. The wheel pulls in and out - more of that to come.
Don't worry about the round dials on the front just yet - let's have a look at this bottom part. This is the footplate (the silver metal plate) and the feed dog (thats the grooved, rippled silver metal where the needle will go in and out of). Lots of little bits to help you in the area, but again, we don't need it right this minute, We have more important things to do.
With me so far? We have looked at the overall layout of your machine - the part that plugs in, the bits that whizz round and have opened secret compartments to find the bit that holds the spool. Now we are going to be extra brave, and tease open the spool case - that's the silver case that holds your little spool (the spool is hidden at the moment, try to contain your excitement).