Welcome to the forum. Glad you have felt the need to propagate Islam. go to the Quran forum, find the commentary threads and study them. studying Islam is the first step because it will give you a strong foundation. you can also find online lectures to hear, including the ones that tell you about dawah-giving, dawah training etc. Abu Ameena Bilal Phillips has some dawah training videos you can find on youtube. also iera.org has some videos you can watch.
Another thing to do is to get islamic leaflets and give them out or email Islamic information to ppl. for example, you can get some info from the site islam-guide.com and then send it to your friends. this is not the most fun kind of dawah giving. it's much better when you write your own leaflets and speak from your mind instead of copying from here and there, but you need knowledge for that. so do both together. start studying Islam, even a half-hour daily or several days a week, on a regular basis, and also get some leaflets from well-known sources (such as WAMY) and give them out - if allowed in your area, or use them in your dawah giving.
May Allah reward you and make you successful and sincere in this great endeavor.