INSERT Among 3 Tables And 1 Is A Junction Table

Looking for some help here, so thanks for any input. I'm a painfully new newbie to SQL scripting.

Situation:
I have a simple database to handle an organization's events. Those
events are categorized and may have more than one category assigned to
each event. I need a maintenance Web Form to update their events.

Set
Up (so far): I have a CATEGORIES table. It has an auto incrementing UID
and a Category name field. This table will be updated so infrequently,
I plan to update it manually (no need for a maintenance Web Form). Next
is the EVENTS table. It also has an auto incrementing UID along with
several fields (Title, Location, DateTime, etc.). The junction table is
named jEVENTSCATEGORIES. It has its own auto incrementing UID along
with 2 fields named for the primary keys (UIDs) in the other 2 tables
(EventsID and CategoryID).

Goal: On the Web Form, I have a
CheckBoxList control that's populated by the CATEGORIES table. One or
more categories can be checked for each event. I have a FormView
control that allows Edits and Inserts.

Need: I need to know the
INSERT statement(s) required to insert a new record in the EVENTS table
and then to update one or more rows in the junction table
(jEVENTSCATEGORIES).

My Assumptions: I know how to create
SELECTs and INSERTs and whatnot, but I'm not certain how to create a
second INSERT statement that is based on a variable (or output) from a
previous action. So any help would be MUCH appreciated. Thanks for your
time!