How to set a goal?

I tried to set a goal few times in my life but have none I can call a success.

To set a goal, you need a number (something measurable), duration to achieve, realistic.

The hard part is the monitoring part.

Say you are targeting to earn $25,000 a month by end of year 2010.

To achieve that, your plan should be based on smaller target/goals.

e.g.

Jan - $5,000
Mar - $7,000 (addn $2k)
Jun - $10,000 (addn $3k)
Aug - $14,000 (addn $4k)
Oct - $19,000 (addn $5k)
Dec - $25,000 (addn $6k)

Then need to think the plan how to achieve that. e.g. additional $2,000 from Jan to Mar.

To monitor every month on the achievement. Whether you are close to your goal or it's just unrealistic and unachievable.