More detailed installation instructions?

I'm new to both roundcube and SQL. I'm trying to get roundcube to work with a sqlite database, but when I try to login I get the following errors:

DB Error in /home/www/html/roundcubemail/program/include/rcube_db.inc (63): DB Error: no database selected

Fatal error: Call to undefined function: query() in /home/www/html/roundcubemail/program/include/rcube_db.inc on line 119

My guess is that I've configured db.inc.php incorrectly. Do more detailed installation instructions (with examples, preferably) exist somewhere? I have been unable to find any helpful documentation for newbies. The installation instructions are a nice general outline, but more details would be really helpful.

Thanks.

H.S.