We have a list of Frequently Asked Questions on the SUNDIALS FAQ page. The topics addressed include build and installation procedures as well as usage issues.
SUNDIALS has an active user community including numerous users who readily comment and give brief help to other users. If you have a question not covered in the FAQ, please join our Mailing List and submit your question there. Also, through the mail list, you will get updates on software and the opportunity to help other users. The list is fully moderated.
We have a page on Usage Notes for handling systems with unphysical solutions or with discontinuities.
Lastly, we like to include references or links to software that uses SUNDIALS. Please let us know of your use here.