Sources you will find in these resources are written for scholars in economics. Many of them will be at a level beyond what you have read in the past. However, you can still glean much information from these sources by trying to understand their main points and by examining the sources they cite.
Use the Econlit database to focus on the literature written by economists.
Working papers can be a good way to find the most current scholarship. Older working papers often have been published as journal articles. They are often shortened for journal articles, so you might still want to look at the working paper version, which may contain more data and in-depth analysis.
Google Scholar has lots of scholarship in the field of economics. However, it can be difficult to sort through all the literature from other disciplines.
JSTOR has a relatively small collection of reputable journals. For the most part, the articles you find here will be at least 5 years old.