Welcome to MobileRead dandan. Glad that you found the place.
There are a number of utilities listed on the
MobileRead Wiki Conversion page that may help. A lot of people have had great luck with PDFrasterfairian. I have used many of the tools there but this is one that I have very little experience with. The developers are around here someplace and if you have a problem with PDFrasterfairian they are quick to jump in and help. Just be sure to include the name PDFrasterfairian in the title of the post.
Keep us informed as to how this works out for you.