Prepare for the campaign before launching into the it.
Using the keyword planner helpful to preparing to launch your campaign. There are three main things about getting your campaign set for launch. Know how much you are willing to spend each day. Plan your keywords/keyword phrases. Write your advertisement. These three things work together to make your campaign functional. It is very important to choose the right keywords, if you are too general in your keyword choice your ad will show up when people search your keyword but it wont be related to their search. This will hurt your click through rate. If you are too specific with your keywords people wont ever see your ad because no one will type in the exact phrase to get your ad. 2-3 word keywords are great because you get some additional specificity and you can find out the balance.
You can have multiple Adgroups set up containing some keywords and you write your ad according to those keywords. I sell photography, so I will have an Adgroup called portraits where I advertise my portrait photoshoots and I will have another group called Fine Art where I advertise for my photography prints. The more specific your Adgroup the better off you will be finding what ads are most successful.
A limited budget can limit your AdWords effectiveness but money is not everything. Whenever someone clicks on an ad of mine I get charged for the ad space. I bid on a spot for my ad to show up and that can only happen as many times as I can afford to do, which is set up in your budget.
Ben Designing 