If my manuscript is rejected, can I “fix” the problems the reviewer notes and resubmit?

Yes. Your reviewer will make some brief comments about problems he or she detects in your manuscript. The basis for declining your book submission may be something simple (like mechanical defects of grammar, misused words, or other editing issues) or more complex (dull prose, fuzzy logic, unclear message). Another draft might fix some of these shortcomings. Regardless, if you send it again, it will be treated as a new submission and require a new fee and Book Information Form. The reviewers cannot be expected to remember an earlier manuscript, since each reviewer is looking at dozens or even hundreds of manuscripts a year. Our assumption is that each submission is equivalent to an item submitted as “ready to go” with a publisher. If your work is a first draft, you should polish it more before investing in the evaluation.
If rejected, you may want to first consider a site such as www.honestediting.com  that offers more in-depth help in the areas where a manuscript and needs to improve. Honest Editing is a new affiliate of Writer’s Edge Service.