If you don't have a viable alternative and you are wiling put in the work, why not. I would recommend the well known book: Patent it yourself, by David Pressman and the less well known book by Ronald Slusky: Invention Analysis and Claiming. Although provisional applications do not need claims, seeing the thinking behind claims should help you with understanding the heart of what patents are about.
Look at a couple of issued patents in your field so you don't model it to closely on an outlier. Good luck.
Pressman, D. 2014. Patent It Yourself: Your Step-by-Step Guide to Filing at the U.S. Patent Office 17th Edition. NOLO, 656pp. ISBN: 9781413320442.
Slusky, R.D. 2012. Invention Analysis and Claiming: A Patent Lawyer's Guide, Second Edition. American Bar Association, 374pp. ISBN-10: 1614385610.
