What is the best way for me to have an index on a FK field in a table with SQL Server? -

i have following:

        create table topic (             [topicid] int identity (1, 1) not null,             [topicseq] int not null,             [subjectid] int not null,             [name] nvarchar (50) not null,             [version] rowversion,             [modifieddate] [datetime] not null,             constraint [pk_topic] primary key clustered ([topicid] asc)         )"; 

i thinking if need find topics subject take long time. if add index subjectid improve every query automatically , best kind of index me add?

an index on subjectid cheap. don't want unique index, it's either clustered or unclustered. i'd go clustered because index not wide (32 bits) though there lot of non-unique values.