I've already created a sequence in PostgreSQL 9.1 by just setting my primary key to 'serial' data type. I know this is short hand for a more complex 'CREATE SEQUENCE' statement however I am wondering two things;

1. How to take my existing sequence and adjust the start value before I start dumping in data?

Code:
\d users_users_id_seq
     Sequence "public.users_users_id_seq"
    Column     |  Type   |        Value
---------------+---------+---------------------
 sequence_name | name    | users_users_id_seq
 last_value    | bigint  | 1
 start_value   | bigint  | 1
 increment_by  | bigint  | 1
 max_value     | bigint  | 9223372036854775807
 min_value     | bigint  | 1
 cache_value   | bigint  | 1
 log_cnt       | bigint  | 0
 is_cycled     | boolean | f
 is_called     | boolean | f
2. How do I create a future sequence in PostgreSQL and set the specific start_value before the sequence is created?