hi the ppi/dpi should be up to what and how good would u like to present your work. say this needs to be a high res file for a client, than i'd sugest at least 350dpi for bitmaps images, if vector art than it wouldn't matter. and also the size needs to be adjusted, the higher the res and size the better print one gets.... however if this is to be printed on a newspaper or something like that than it can be at 150.... just my two cents