Is it easy to start a business?
I'd say it's both easy and hard to start a business.
Really the most important thing you need is commitment. It takes a certain personality type to run a business.
Take my own small business. I sell software to large businesses. Writing the software was the enjoyable bit (well if you're a computer programmer then you usually enjoy the bits of the job that involve writing programs). What was tougher was all the other bits I had to do to get a piece of computer software off of my hard disk and onto the web so people would actually hand over $50 to buy a copy off of me.
And that involved making the program look nice, writing help documentation, designing a website, marketing the products and answering emails from tentative buyers. All of that took a lot of effort to get the finished software product to actually put money into my bank account.
And as you might have guessed I didn't make a cent from this business until I actually put the "buy now" button on my website. So again, commitment is key to starting a business.
What you will find is that if you have the certain mindset that is required to start a business, then you'll find it easier to start more businesses in the future. Start with selling cupcakes, then move into real estate or import/export! The sky really is the limit when you start your own business.
As to business ideas, it's generally easier if you start a business based around something you know. So whether it's a hobby or related to your day job, it's best to start with familiar territory.
I now have around 25 small website businesses. They're in a wide variety of niches. Yet they're all centered around things I know about, including software, travel to countries I've visited and helping people recover from health problems I've personally suffered from in the past.
Talking of day jobs - it's often quite easy to start a business based on your day job. If you're an accountant by trade, then why not start your own accountancy service?
Spinning off parts of your day job are also quite lucrative. I used some particular software tools in one day job I had, and I realised that if I built some of these tools myself then I could have a nice little business on my hands.
One other tip is to start small, and start cheap. If you want to start selling items online, then start an eBay store. This is a really cheap way into retail. If things go well, then build your own online store later, but eBay is the best place to start.