For more basics see: uspto.gov/patents/basics/essentials (image credit: USPTO)
For more details review USPTO's Multi-Step strategy that includes links to more resources.

Let's say you're looking to get a patent for your new flying car that your company has designed here in the USA. It is capable of vertical take off and landing plus is powered by completely renewable energy (like a certain movie franchise from the late 1980's)... Probably you'd like to protect how it flies - take off, landing, flight. How would you get started?
(image: NASA.gov)
*These include VT subscribed access - if non-VT affiliate, search and access over the regular web when not using a campus computer
There are 5 main categories as you go from your idea through maintaining your patent (see details on USPTO's Patent Process Overview):
Note: IEEE Xplore includes patent citations, not filterable in searches for patents.