There are a number of essentials steps which you need to do to get your Wordpress to load really really fast. Some are simple, some are a little bit more complicated.
1. Get yourself a GOOD hosting service - this will make absolutely the biggest difference. Make sure you go for the highest plan you can afford. Simply put, the cheaper the service you go, the slower your Wordpress will be.
2. Install a caching plugin. This makes sure that Wordpress does not load and recalculate everything every time a user visits your site, but reuse a copy from a previous hit. This allows Wordpress to be faster and allow more simultaneous users
3. Get a good themes which is optimized for speed. Many themes get bloated with all sorts of stuff and they start getting slower and slower.
4. Get rid of as many plugins as you can. Each one of them is increasing the load time of your Wordpress website
5. Enable compression of files. Makes them smaller to send and will thus take less time.
6. Optimize images, make them as small as possible. Once again, smaller images, less time for transfer = faster website. There are various plugins to do this, though ideally as per point 4, you should do this BEFORE you upload your image rather than fix the problem with a plugin.
For more details follow Wordpress development tutorial on Yiioverflow.
