You should not go into Adwords before you are pretty sure about getting it right the first time. Here are some basic tips for you to know adwords.

You need to turn off content targeting and search network. Do you know where to look at these ads? No. Leave them alone until you feel confident that you know where they'll be showing and that you can make them work. You should get comfortable with Google first. Conversion rates and CTR's change dramatically for each search property, not to mention content targeted ads. Get acquainted with Google before you move on to the others.

You should test different creatives and positions. How much of a difference will being in the first position, as opposed to the second, third or sixth position make, for your net profit? The answer is that it depends on your creative, industry and who else is bidding on your keywords. The bottom line is that you should know. Test your creative in each position and work out where it will be most effective, from an ROI point of view. You can also test your creatives. Write 5 or 6 different ads and set them to run evenly (Google will run the one which performs best by default, but you can set them to run evenly in your campaign settings). The creative which gives you the highest ROI is the one you should go with. You should probably run this kind of test for more than just a day.

Optimizing your landing page is helpful. The landing page is the page which the person who clicked on your ad will see when they come through to your site. Don't use your homepage as your landing page unless it deals only with selling the product you're advertising. For instance, if you're selling posters, have a landing page for 'flower' posters and a landing page for 'Car'. You can even go one better and have a landing page for each poster, so you'll have a page for 'sunflower posters' and 'bmw 5 series posters'.

You also need to optimize your creatives.  Optimizing creatives is another topic entirely, but there are some easy wins depending on, again, the strategy being appropriate for your campaign): one, for example, is using a keyword specific url. If you're selling Nike AirWalk shoes you might want to set the URL on your creative to display.Keep in mind that this has no relation to the real click through URL, but it looks better than your domain name and certainly better than a long line of numbers. Keep this relevant however, because otherwise you could cheese people off if they don't find what they're looking for. Another easy win is to not include superlatives, like 'world's best' and 'most loved product' or ALL CAPITAL LETTERS. Google will just disapprove them. If you do mention a price or something else (like: the UK's best selling mobile phone) then you must back that up on the landing page for the ad. One of the most important things to remember that the ad copy is one of the most crucial things for making people click through. This sounds obvious, but there are a lot of very bad creatives out there.