I am creating a wordpress plugin for Wordpress, and I have to store some good info from the form right into a table within the DB.
You will find most likely plenty of pages explaining how to get this done, this being one of these: http://codex.wordpress.org/Function_Reference/wpdb_Class
But are there more pages speaking about best practice for getting together with th Wordpress DB?
Found a couple of more pages that could be helpfull:
Unless of course you have to make your own complex table structure I'd suggest while using existing tables to your requirements. There is the options table, user meta table, and publish meta table to utilize. All of these have built-in apis for convenient access.
I have not found much real will need to go outdoors of those tables (yes, you will find exceptions, I have done them myself once the data needs are complex) however these meta options all make use of a text area within the db to keep the information, so there is lots you are able to store here if it is simple data.
In case your information is simple then consider storing your data in one of these simple places as individual options or even while serialized arrays.