I used to own a Business, which I turned over approx $120,000 in the first year alone.
The key things are:
1. Customer service - your first customers are going to be the ones to tell others how good/bad you are. If you're going to barely break even on something in order to satisfy a customer, then do it. You'll reap the rewards later. Nothing is higher than customer service when starting a business.
2. Availability - you have to be willing to go the extra mile for EVERYTHING. There's a little thing called COMPETITION which will have a big impact on your success. If customers know they have to wait an extra 3-4 days for your product and are making a minimal saving, then believe it or not they'll go for the expensive but faster option. How many people will just go out to an electronics store and pick up an item even though they know they can buy it cheaper online? Ever done it yourself?
3. Consistency and commitment - if you say that you're going to do something for someone, then do it. Don't mess them about. If you are serious and are looking to advertise somewhere on a regular basis, then KEEP ADVERTISING. Have you ever opened a local newspaper and read the trade adverts? Would you go with someone who's there on a regular basis, or someone who advertises maybe every month or so?
If you manage to fulfill just these three things, then on average EVERY customer will tell at least 2-3 people. That's free advertising. It's also the most proven effective form of advertising and will gain you 5 times MORE customers than any written advert.
The key to a successful business is *REFERRALS*. You will not survive on just advertising alone.
Customers who have a good experience tell a handful of people.
Customers who have a BAD experience tell EVERYBODY.
Money- Obviously you'll need capital. Sit down with a banks IFA (Independant Financial Advisor) who usually will talk to you for free. Explain to them what your intentions are and draw up a business plan. Get yourself an accountant (they're not as expensive as you might think - more importantly, they'll save you packets in taxes.
Premises - work from home for now. Don't go buying warehouse space. If you're just selling chips for now and chipping a few Xboxes, I'm sure you can find room in your current place for this. Better still, you'll be able to offset some of the mortgage costs against business costs.
Finally - Skill. If you're going to be doing this for profit, then you're going to need to have 110% confidence in your work. If you feel that your soldering skills aren't as good as they should be, then be honest about it. Get practicing.
You're probably reading this thinking "That's a lot to do". You're starting a business. This isn't to be taken lightly. You want to succeed so there's no point in doing it half-heartedly.
Good luck
Martin