See my blog on announcements
If you are not one that is creative you can also buy professionally designed and printable announcements online. If you are into things that are special you can add a picture of the new baby to make it look like it is a birth announcement that you made yourself. Various websites are now available that give you the option of uploading a photograph of your new baby so that it can be made into announcements. Then you just need supply the birth information. Some of these websites even let you pay a one time fee and then you can print out this many announcements as you want.