You will get to the dataset upload page where you have to specify the name of the dataset, a logo (optional) and the dataset itself.
IMPORTANT: The dataset can be in one of the common RDF serializations and must be syntactically correct. You can both check and clean a file using serdi
serdi -i ntriples -o ntriples dump.nt > dump_clean.nt
After uploading the dataset, it will appear in your profile.
The dataset is now ready to be queried!