ok, i've owned my own business and i've sold/maintained indoor plants a couple of different times.
i'm not really sure to tell you about owning your own business - whole books have been written on the subject and none of them tell you everything you need to succeed. just getting out there and marketing yourself/product is the most crucial part of getting off the ground. from that standpoint i would strongly suggest you get your own domain name as soon as you can afford it. tagging onto an aol domain is not very professional in this day and age. not that the web is going to be your main source of revenue directly, but once you get going a bit and people have heard of you, many will want to find you on the web to get more info, directions, etc.
i used to sell houseplants by loading them in my van and going office to office. first time i worked for a guy that kept a small retail location and got people like myself to work on commission and go out and sell them. there were usually around 6-10 of us working for him at a time. made a lot of money some days and very little on others. but it was fun. from that i picked up a couple of side jobs maintaining the plants i sold to businesses. easy money is all i can really say about that. stopped in once a week to water them and prune them occasionally. guaranteed i would replace them if they died which i knew they wouldn't given as they had perfect diffuse light that was never too hot to dry the plants before i got to them again.
the second time i worked for a guy who simply had a warehouse and sent the crews out from there. it was harder since there was no established place of business. didn't seem as legit to people i think. poinsetta's at xmas were the best because no one really expected them to survive anyway.
bottom line about how i sold plants - people will impulsively buy nice big lush plants that are right in front of them. or will ask about plants they have been searching for and buy them if you can get them for them. businesses that buy them will buy big and want to protect their investment and that's where the maintenance comes in.
if any of my experience sounds vaguely similar to what you're doing (or would like to do), feel free to ask more specific questions. or pm me and we can set up a time to talk on the phone if you would like.