Researchers (in the areas of Linguistics, History, Humanities, ...) often find their work difficult when they want to analyze and investigate a topic or an event, as the information is spread across various platforms and in different formats. These difficulties are also felt when it is necessary to gather different documents to create a corpus. This problem moved us to create a systematic approach to building an online corpus. Our approach aims to: extract information from news and comments available in online newspapers or social networks using web scraping techniques; process it using Natural Language Processing techniques; store it in a repository; and finally present it on an online platform. To validate our approach we collect news about a very current topic, the War in Ukraine. In the case study that is described to illustrate the proposal the news were extracted from two Portuguese newspapers and the social network Reddit. The corpus created can be consulted and explored in a web platform called GUCO, that is also presented. With this project we intend to overcome the problems mentioned and make a contribution to the area of Digital Humanities.