The first thing you want to do when getting started with Zotero is download it to your computer. Zotero provides downloads for Windows, Mac and Linux computers. To start downloading it, simply click the link below and then click the big red box in the upper corner of the website that says "Download Now."
Once you have downloaded Zotero, proceed to install it and follow the on screen prompts until it is complete.
After downloading the software, you will want to register for a free account with Zotero if you want to sync citations and/or files. To do this, simply go to www.zotero.org and in the top right corner of the page, click the blue "Register" link. This will take you to the screen shot you see below. All you need to do now is fill in the required information and you are all set!