I had a new writer ask me this. I thought I would share my advice I sent him. If you have anything to add (I seriously can't imagine this group doesn't have an opinion - and that is why I keep coming back) please share.
Three tips I wish I new when I started my first story on SOL:
1) There is a difference between a proof reader and editor and you need both. An editor will help you with the story. For example continuity, character development, and pulling you back from the ledge when you insist on doing something stupid. They also tighten up you writing. A proof reader fixes grammar and spelling and catches minor issues. While an editor will catch a lot of the grammar and spelling errors, that is not their main job in my opinion. If you have a good editor it is more of a collaboration IMHO. Believe me - you need both. Very few people can self edit for the simple fact that if you wrote it - it sounds fine to you...
2) Create a character page. I do an image search and put it right under the character name. I then fill in the basics (age, height, occupation - you need to figure out what is important to you). I then write a quick bio to give me a back story. I find I constantly use this. It helps to have a picture to be able to refer to.
3) Create a basic road map with an end in sight. I use two things. The first is a calendar. This is good for a saga like Stupid Boy. I put in all the important dates (birthdays, football games, vacation time). I then write a one or two line planned chapter summary.
I am a serious train of thought writer. Many times when I sit down to write I have no idea what will come out. I just start to write. I need the structure the calendar and chapter summary give me. It helps me focus on what the intent is for the chapter and I usually am pretty good at reining in my tangents. Sometime though, your best stuff comes from unplanned tangents that can send your story off in an unexpected direction. Change is good - as I used to preach in my project management days.