One of the best pieces of advice I've received about sewing machine maintenance, is not to wait for the machine to tell you it needs oil. I don't usually sew every day, but I sew most days. A tiny drop of oil once every week or two is great. Do NOT over oil. Wipe excess away and always wipe off excess with a fabric scrap.
1. Remove bobbin, bobbin casing, foot and thread. You can remove the needle too if you think you may get into trouble.
2. Take off stitch plate. For mine, you just push in the corner and it pops up.
4. Get your nifty little cleaning brush that comes with every machine and go crazy.
5. Add a tiny bit of oil (when required).
6. Put everything back in the right spot! This is important. If not, the machine won't work. ;)
I'm always amazed what gunk comes out of my machine even if I had only cleaned it a day before. Push the bush into as many nooks and crannies you can.
Don't blow in your machine. Sewing machines don't like moisture (oil is not moisture). Most important thing to remember is that any sewing creates lint build up in the machine but batting, of any sort, is particularly messy. It takes no time to quickly open the machine up and clear out the lint. Well made machines really do last a lifetime and this simple maintenance will ensure smoother sewing for all.
NB: Your individual sewing machine manual should explain how to strip down your machine for cleaning.