A lot of people install their own car (and home) stereo equipment only to find out it just does not sound or look like they thought it would.
This can be caused by cheap equipment, bad components or not following instructions. More often that not, it is the fact that no one is good at everything
they try or they just plain don't know what they are doing.
The best thing to do is decide if you realistically can handle the install and have the TIME it takes to do it PROPERLY.
Enlist the help of experienced friends, relatives or pay someone to assist if you need to. What it all boils down to is:
Can I afford the time, materials and effort this will take. Especially if I encounter problems along the way.
When in doubt, pay someone who knows what they are doing and will be responsible for any damage that may occur.
If you still want to proceed on your own, read everything you can get your hands on, wait a couple days then read it again. And, keep your
reading material right there with your tools while doing the work.