Google can itself help you in this. Just post this same query on Google & visit Google Adwords Support Page so that you can learn basics of Google Ads there. As a guidance I'll suggest you to invest only if you have the proper knowledge of what you are doing and what you gonna do in future. Yes, you have to make plans, strategies according to your other campaigns and keep analyze the data you are receiving through it.
Answer to your query on How to publish advertisement on Google. Its pretty simple to publish Ads on Google, just follow these steps-
1. Setup an account with you want to publish ads.
2. Set your budget
3. Set your location
4. Choose a network (Can be Search Network or Display Network)
5. Choose your keywords
6. Set your bid
7. Write your ad
8. Enter your billing information
That's done.