Workout goals with importance

Be very specific about your goals. Saying "I want to be able to walk a mile, on the treadmill, in 8 minutes, no later than 8 weeks from now" is a good example. A short term goal should usually be around 8 to 12 weeks in length - to give you enough time to actually accomplish the goal, without making it feel out of reach;
Be very realistic about your goals. While you may want to be able to "walk a mile, on the treadmill, in 4 minutes" - the truth is that you may very well be over extending yourself. Remember that, while you fitness level will continue to increase, as you exercise regularly, you will always face certain limitations. In fact, discovering what these limitations are and then, determining whether you can actually go beyond them, is part of the challenges you will face, as you embark on your fitness program.
 Remember to look at your success and to be proud of it. Unfortunately, too many people spend more time looking at the negative aspects of their workout instead of the positive ones. Don't hesitate to congratulate yourself on a job well done and give yourself a break - you won't be able to accomplish it all in one week or even one year, so take it one day at a time and actually take the time to enjoy the process.
Remember that setting goals is a great idea, but it is also important to be flexible - these goals should change, as your fitness level increases - you should always be looking for new challenges.