Multiple Values for single row

hi iam totally new to databases , as a project i have to design a database of users...they have to register first like any site..so i used stored procs and made entries to database using insert command...its working for now..

now every user will search and add other users in the database..so every user will have a contact list...i have no idea how to implement this...

so far i created a table 'UserAccount' with column names as
UserName as varchar(50)
Password as varchar(50)
EmailID as varchar(100)
DateOfJoining as datetime
UserID as int --> this is unique for user..i enabled automatic increment..and this is primary key..

so now every user must have a list of other userid's.. as contact list..

Any help any ideas will be great since i have no clue how to put multiple values for each row..i didnt even know how to search for this problems solution..iam sorry if this posted somewhere else..
THANK YOU !

if it helps..iam using sql server express edition..and iam accessing using asp.net/C#Hi,

Create a contact list table which includes columns,

UserId,
ContactId

Eralper