stored procedure is used to write queries,if there is an 
error in the query it willnot be saved.In this if there is 
any parameters first declare it,and then the query is write.
Each stored procedure could have a name.We can create the 
stored procedure for any tables in the database.
create database->create table->stored procedure.
format:

(stored procedure name)
(@parameter1 type(size),@parameter2 type(size))


//(query)
insert into tablename values(@parameter1,@parameter2 )

There could be 'n' reasons for slow performance. For tuning 
the performance of a SP we need to know how much resources 
it is using and how much time it takes in execution. We can 
check this using the performance monitor (for example, RPC 
Counter) and execution plan. Check if we are using 
appropriate joins, table defrag, index rebuilt can be the 
solutions.

Store procedure is a pre compiled code
it is doing single task of several task
it is used to reduce the execution time
if we want to call store procedure just we call its name

The statements from above are correct but one main thing 
that might speed a proc up is the naming convention.
If you create a user defined Storproc and you name it by 
using the "Sp_" prefix  SQL thinks is a System Store Proc 
and goes to the Master DB to look for the Object instead of 
looking locally.

Stored Procedure is Precompiled set of quries. Stored 
Procedure performence fully depended on this queries. First 
Look the queries performence using Execution Plan. After 
find the Queries, just check the Index(for table used in 
query) and look the join conditions between tables in the 
query. - This is way we need to approch to tune the SP.