This is not going to be an exhaustive list or ultimate list of what to be aware of before setting up your business. Just an essential checklist. Feel free to add to it via the comment box.
1. Be incorporated/registered from day one.
Avoid falling into the trap of doing business like a road side mechanic. Using your personal account, having no registered company name and having no registration documents.
In the beginning, when you are doing the business on the side while still in your full-time job, it may not be a big deal. After all, the money from it is an extra income and any person/company who chooses not to deal with you because you're not registered is just allowing you more time for your main occupation. But when you are full-time in business, the big clients won't deal with you if you are not registered, even if it's pepper you are selling.
2. Do your tax registration from day one and do your monthly VAT filing.
As a business you are expected to fill a VAT form every month and file at the FIRS, whether you did any business that month or not. If you didn't do any VAT-able transaction, then you simply fill NIL everywhere they were expecting figures and you pay nothing. While failure to do your VAT for any month attract a fine, that can easily be compounded.
Also, when dealing with some companies. You'll need to provide your VAT certificate.
3. Have A Company Profile/Brochure, Company Bank Account and Company Address
Again, even if its pepper you are selling.
4. Have a website and use company domain email addresses.
To be continued... (part 2 here)