another tip. you really never want to skew anything unless its an artistic effect you want to achieve.
also, when you get other graphics you want to put in your graphic, get one bigger than you need. if you enlarge something it will be blurry or get jaggies if you dont have anialiasing on or something.
there are shortcuts to make things keep their perspective when you are resizing. i cant remember what it is for PSP7, its one of the alternate function keys like shift, control or alt. you can hold one of these and then resize with your mouse and it will keep its aspect. you can also to layer or object resizing through menus for more presise measurements.