1. I'm going to be straight up about this, you're not going to have a 401k, or benefits of any kind (medical, dental, corporate SWAG)... you're on your own. Do your homework first before cutting any ties and for Pete's sake, don't EVER burn any bridges when planning on a solo career. Fortunately my husband has great benefits through his work place, as well as his Navy retirement, and I have benefits as well from my former employer as well as my disability that I EARNED. (Some people are confused about the disability that you EARN) Throughout my 30 year working time I paid into disability, and after my Dr. pretty much said 'you're done' I applied for disability. That's as personal as I'm going to get on that subject, if you want more information on that, e-mail me. Just do your home work, period. This is your baby, no one else is gonna raise it for you.
2. Brand it, then Blog. Blog, and blog some more. When I mean brand it, I mean get a logo (make your own, don't steal, that's a whole other can of worms you don't want to deal with as a start up) take pictures of your merchandise and create a catch phrase about the work you do. Facebook, and dare I say this word... Twitter... Get out on the social networks and make yourself known. I use Blogger through Google. It's easy to use and has lots of templates that look professional that you can adapt with a certain amount of skill. Linked In is nice (ahem), but beware, you can be seen, but for a ridiculous price they can 'allow' others to contact you. (They're like an angry mother who has grounded you...I do not recommend them for start ups).
3. It's not all sit at home behind the computer in your jammies, you will have to get out in the 'real world' and network, and meet with others if you plan a client rather than consumer based business. Client based is more intimate and requires more attention, consumer is the shop and ship. Even with shop and ship, you will have to get out there, unless you order your boxes and shipping materials delivered to your home (USPS and Fed Ex does that, not sure about UPS) With clients you will most likely have to meet them face to face. Especially if you have a photography or PR/Social Media type of business like I have. You're going to have to network for them as well...so don't throw away your 'office clothes'... just make sure they still fit and are presentable. Common sense people, common sense.
4. Be sure to have your I-9 and Tax information prepared come January. See the IRS website for that kind of info. Do your homework, I'm not going to do it for you, otherwise I will charge you... :)
5. Be on friendly terms with your UPS, Fed Ex Office and US Postal Service people if you plan a shop and ship kind of business. They can make you or break you, be kind to the hand that feeds you. I've seen so many people get that 'They're civil servant' attitude towards their carriers, and well, it bit them in the proverbial tushie.
6. Before you lay down the bucks for a .net or .com ....research what's out there and what you can afford. Also, be sure that you can either build your own site with a template that you can import to your .net or .com, or have the cash ready to dole out to some out of work coder who needs a job to get through grad school, or to pay their way into Comic-Con to build your site for you. Or better yet, an up and coming Techno-Diva looking to hone her skills.
7. Network through your friends, but ask their permission first. Don't start posting your brand on their FB page or hashtagging your name all over their Twitter. Baaaaaad idea. That's a bad way to end a friendship, because 9 out of 10, they will tell you to knock it off. I love my friends, I'm just not their political or business platform on my FB page. I have to say this because I've had it happen. I've had the Amway and 'home business' trolls in my crafting message boards years ago.... they're like bamboo, irritating and hard to get rid of. I tell them once. Politely. Then I push the 'ignore' button.
8. Get your own e-mail address, do not use your home/personal one, and ABSOLUTELY do not use your current employer e-mail address (had someone do that at my former job, and it became his former job, I have to say this, because it has been done) and not with a 'cutesy' name, keep it along your 'brand' and professional. If you're marketing a hard line of survivor equipment no one is going to take 'firstname.lastname@example.org' seriously if that's your business e-mail address.
9. Save EVERYTHING! Every receipt from every purchase you have made that's business related... and no, as much as it pains me to say this, chocolate is NOT a business expense. Business related is software and computer hardware that you use to make your business work (No, World of Warcraft accounts do not count), office furniture (ergo chairs do fall under the realm, sparkly chandeliers do not), business lunches and social engagements (with clients, you feed yourself every day and you do not count that as a tax write off do you... no, didn't think so), transportation (if you are meeting clients, and be sure to track mileage, there are smart phone apps to do so), and general 'office supply' expenses (paper for printer, ink cartridges, business cards, not 'twinkle lights' for your home office or Bose stereo speakers...)