Lately I've been asked about what niches are hot and that's a hard answer because things are coming and going at such a fast rate its hard to gauge at the moment. As far as newbie niches go, they have to be extremely careful before they just jump out there as with anything else because remember, the weasels stay up day and night figuring out ways to seperate you from your money.
1. Just because something looks good to you doesn't mean you have to jump into it head first, see if they have an affiliate or re-seller program attached to the company and if they do, then work that and see how it goes.
2. If you already have a skill, use it. You don't have to break your neck re-learning a certain skill set if you already have a bankable skill. Just hone it down and get it up to date and look for an affiliate that matches your skillset.
3. You don't have to re-invent the wheel just make a better mousetrap, in other words you don't have to wrack your brain looking for the newest thing, there's nothing new under the sun.
4. By the time you've seen a pre-launch the Guru's have been working it for months with their lists. Try to find a site where the Guru's hang out so you learn about their pre-launches before it hits the market. One of my favorite Guru hang-out spots is The Warrior Forum.
5. If you get into a crowded niche make sure you stand out, be visable, write often, offer what they don't, be where the people in your niche hang out, you know my saying, don't try to sell a steak to a vegetarian.
6. Last but certainly not least, there are millions of niches out here, the trick is finding the right one for you not someone else. Just because something works for someone else doesn't mean it'll work for you and the reasons will vary like skillset, marketing money, niche saturation among other things.