Storyline planning
Plan everything. Right from the very start of the story, through to the ending. Then, once you have finished doing that – read your plan from start to finish. If you think it will still make a spectacular story after you have finished, then you can go ahead to the next step.
If you don't think your plan cuts the cake in terms of storyline, you need to adjust the plan to make it a good story. Brain-storming helps! A big piece of paper and lots of colourful pens are the best tools to use for this particular activity. Then stick the paper on the wall in front of you, and dream up some new storyline or plotline that will make your plan even better.
The most important thing to remember is that your plan is a ‘living’ document. Your plan should be continually updated and reviewed throughout the process of writing your book. That way, you have a good birds-eye-view of your story as a whole. It’s also good, because if you think of anything that you want to add to the story, you can see how it will work in with any plots and twists that you might have in mind and you can figure out ways to tie it all together with the ending.
Research
No matter what your book is about, doing research is absolutely imperative. It is up to you on how much you do, or how little.
The internet is an amazing tool, and everything is right at the touch of your fingertips. If you are setting your story in an area that is unfamiliar (like I do all the time) Google Earth is amazing. Not only does it have photos, but it also has Wikipedia links all through it, as well as the Zoom button, so you can get up close and personal with the area. Whoever designed and developed Google Earth is my hero. I should really write them a thank you letter of some sort.
Of course to actually get to know a place, the best way to do research is to actually go there, however some of us poor writers can't afford that sort of luxury. It's also good to speak to people who have been there, or look at the websites promoting that area. That way you can get a feel for the culture, atmosphere, and landscape.
The other sort of research I often delve into is personality profiling. I do this for the development of my characters, although generally you have a pretty good idea of what sort of characters you need from your planning. But doing personality profiling can help give your characters more depth.