Immunological Genome Project: https://www.immgen.org/

ImmGen is a large transcriptional profiling database of immune cell subsets

Immunological Proteome Resource: http://immpres.co.uk/

ImmPRes is a large proteomic profiling database of immune cell subsets

Janeway's Immunobiology (5th edition): https://www.ncbi.nlm.nih.gov/books/NBK10757/

Although this textbook is now in the 9th edition with many new updates, NCBI provides free digital access to the text and figures, which is a great resources for learning the fundamentals of immunology.