how to interpret plan table in oracle 10g

 Hi Guru's,

      How to interpret the plan table? Please find the below output which i got after the explain plan of that query.

Plan hash value: 2308505597
 
------------------------------------------------------------------------------------------
| Id  | Operation          | Name                | Rows  | Bytes | Cost (%CPU)| Time     |
------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT   |                     |     1 |     5 | 17490   (2)| 00:03:30 |
|   1 |  SORT AGGREGATE    |                     |     1 |     5 |            |          |
|   2 |   TABLE ACCESS FULL| EDW_OP_MAIN_TREND_R |  2295K|    10M| 17490   (2)| 00:03:30 |
------------------------------------------------------------------------------------------

Always taking time to retrive the data from the database on particular table.(Not only this table).How to find the slowness factors from the explain plan?

Please explain me step by step..

Thanks in advance,