There have previously been asked for a tutorial in the HTRI.

As a matter of facts in the help menu of HTRI one can chose tutorials.. and you have short tutorials in how to enter data in say XIST. This could help one to get family with where and how to enter data for a new case. And also have a look in the supplied examples.
But I still believe a program like HTRI required some basic knowledges about heat exchangers say from good books or from leaning - first then one can understand most of the data the calculation delivers in the reports.. :-)