I have five earrings. Both lobes, my helix on my left side (what you are calling the cartilage ridge, a conch on my left side and a daith on my right side.
Forget this sea salt shit for cleaning. The best thing you can use to clean a new piercing is dial anti-bacterial soap. clean the piercing 1-2 times a day while in the shower. let the water run over the piercing for a 1-2 minutes to wash away any crusties, apply some soap and make sure to rinse thoroughly. and you should clean your piercing last in the shower after you have shampooed and conditioned and anything else. you dont want any extraneous product left on the piercing.
As for where to get this done. go to a piercer. I personally go to venues by maria tash in NYC but that doesnt seem like an option for you. I have been pierced by Maria herself, and by Meg there who is also amazing. Meg has lots of body mods (tattoos all over, tregus piercings and a pair of conches, plus stretched lobes). Maria on the other hand had dainty little ear piercings and a daith and nothing else taht I can remember. She used to have stretched lobes from what she told me. The number of body mods says nothing about your piercer other than their personal taste. I dont care how many piercings my piercer has because guess what it is far and few between the piercer who pierces themself especially for more intricate piercings. It would just not be smart, so anything they have is not an indication of their workmanship or dedication to the craft.
Go to a piercer who will use a hallow needle and not a gun. I made the gun mistake with my helix (16 years old) and my first ear lobe (15 yrs old). when I went to a piercer to get my other lobe done (Maria Tash) she spent the time to make sure that the two would be even and at the same angle etc.. which one cannot do with a gun. When Maria did my conch she went out of her way after I payed for a basic steel cbr to give me a gold one because she didnt like the way that the steel ring looked and they didnt have anymore steel in the store (gold is considerably more expensive). that is a sign of a piercer who cares and who knows what they are doing. Talk to your piercer before you decide anything. a good place will talk to you about what you are going to do and what you want and spend time with you. anyone who tries to rush you is not things is not worth your business. When I got my daith done I had actually gone in looking to get a rook but I am much happier with my daith then I would have been with a rook, and thats because they took the time to talk to me and give me options and work things out.