These are papers—some old, some newer—that provide fundamental ideas that every ERP researcher should know.  Steve's personal favorites!

Donchin, E. (1981). Surprise!...Surprise? Psychophysiology, 18, 493-513.

Donchin, E., & Heffley, E.F., III. (1978). Multivariate analysis of event-related potential data: A tutorial review. In D. Otto (Ed.), Multidisciplinary Perspectives in Event-Related Brain Potential Research (pp. 555-572). Washington, D.C.: U.S. Government Printing Office.

Groppe, D. M., Urbach, T. P., & Kutas, M. (2011). Mass univariate analysis of event-related brain potentials/fields I: a critical tutorial review. Psychophysiology, 48, 1711-1725.

Keil, A., Debener, S., Gratton, G., Junhöfer, M., Kappenman, E. S., Luck, S. J., Luu, P., Miller, G., & Yee, C. M. (2014). Publication guidelines and recommendations for studies using electroencephalography and magnetoencephalography. Psychophysiology, 51, 1-21. 

Kiesel, A., Miller, J., Jolicoeur, P., & Brisson, B. (2008). Measurement of ERP latency differences: A comparison of single-participant and jackknife-based scoring methods. Psychophysiology, 45, 250-274. 

Picton, T. W., Bentin, S., Berg, P., Donchin, E., Hillyard, S. A., Johnson, R., Jr., Miller, G. A., Ritter, W., Ruchkin, D. S., Rugg, M. D., & Taylor, M. J. (2000). Guidelines for using human event-related potentials to study cognition: recording standards and publication criteria. Psychophysiology, 37, 127-152.

Woldorff, M. (1993). Distortion of ERP averages due to overlap from temporally adjacent ERPs: Analysis and correction. Psychophysiology, 30, 98-119.