New to home audio

Hello everyone. I'm interested in expanding my audio knowledge and learning more about home audio. I've been big into car audio for over 10 years and know a great deal but am a complete novice when it comes to home audio. I'm interested in putting together a custom home theater set up, made up of seperate highs, mid range/bass and a single, large diameter subwoofer. I'm unsure of any brands to go with, how I would go about breaking these frequencies up nor how I would power each. Any help would be greatly appreciated

I'm not sure what kind of budget I would really need to achieve the type of set up I have in mind. I assume it would be a couple thousand depending on what I go with. I understand the theory of how the install can influence output, so I'm shooting for speakers that will perform well, but planning on putting them within ideal, custom cabinets to optomize their performance. I'm assuming most of the money will go into the receiver and amplifiers. Not sure of the exact measurements of my room, but maybe 10 X 20. Average size.

Currently I don't have anything so I would be starting from the ground up.