It's probably going to be a while before 3.56 and larger will be able to have CFW, if you're desperate it's best to acquire a 3.55 console while you still can, because soon consoles will start appearing with 3.56 or 3.60 at purchase.
1. Install 3.55 OFW if below 3.55.
2. Install CFW of your choice in recovery mode.
3. Install Backup Manager of your choice.
4. Install BDEMU355.pkg if you installed Multiman.
STOP! Before you ask questions... READ the first post! RTFFP = Read The F*cking First Post
Yes, A 3.55 "jb" (cfw) is available, no >3.55 "jb" or cfw yet.
Yes, A 3.55 downgrade is available. But not to lower than stock firmware! (What it came with)
No >3.55 downgrade is out there yet.