You can create your own puzzles or put in those found in magazines and other places. To do it, simply press Clear all button and fill board with desired numbers. Then press Lock button, and all numbers will turn black, just like after New game selecting. From now you can start to play.

Hint: When you are creating own puzzle starting with empty board, set Hint level to 2 and check Higlight lonely numbers option. Then fill board with numbers, until you see all empty fields with only one possible number, like below. This means, that puzzle contains no errors and has only one solution. Then lock it, choose desired hint level and start to play, or solve it, by clicking on yellow numbers, one after another :)