Generating New ID

[xor_ax_ax]

I am new to SQL server.
In MySQL when inserting a new record, im locking the table first,
use max(ID) + 1 to get a new ID and then release lock after
succesfully insert a record.

How you do this in MS SQL ?
I try to use subquery like

Insert Into StockGroup Values((SELECT max(id) FROM stockgroup) +1, "test")

Sub query not allowed.

Please help.
Also how get it work in Store Procudure.

Thanks.