Historically, any newly discovered object needed to be "confirmed" by detecting it in the optical band. Catalogs were published with stamp-sized images obtained at the largest available telescope or from sky survey plates (e.g., Parkes catalog identification papers in several issues of the Australian Journal of Physics and Astrophysics Supplements (e.g., Bolton et al. 1977); Einstein sources - Maccacaro et al 1994; QSO identification - Schneider et al. 1992). This probably is still true, although not as general, as we try to "see" what we have just found.
We are probably reaching an information overload with more efficient instruments, larger detectors and an increasing number of facilities. At the same time the technology has been catching up and has allowed us to be able to reach most of these data regardless of where it resides. These notes are just a roadmap to guide the reader through this maze, highlighting some of the more important starting points or stops.
Probably the most difficult part of a project is staring at a blank page and needing to fill it up, or getting some brief description and trying to complete the information. The following section will have a few pointers to information or data useful to elaborate or check new ideas.