  Classical novae are the product of thermonuclear runaway-initiated explosions
occurring on accreting white dwarfs. V339 Del (Nova Delphinus 2013) was one of
the brightest classical novae of the last hundred years. Spectroscopy and
photometry are available from $\gamma$-rays through infrared at stages that
have frequently not been well observed. The complete data set is intended to
provide a benchmark for comparison with modeling and for understanding more
sparsely monitored historical classical and recurrent novae. This paper is the
first in the series of reports on the development of the nova. We report here
on the early stages of the outburst, through the X-ray active stage. A time
sequence of optical, flux calibrated high resolution spectra was obtained with
the Nordic Optical Telescope (NOT) using FIES simultaneously, or
contemporaneously, with the Space Telescope Imaging Spectrograph (STIS) aboard
the Hubble Space Telescope during the early stages of the outburst. These were
supplemented with MERCATOR/HERMES optical spectra. High resolution IUE
ultraviolet spectra of OS And 1986, taken during the Fe curtain phase, served
as a template for the distance determination. We used standard plasma
diagnostics (e.g., [O III] and [N II] line ratios, and the H$\beta$ line flux)
to constrain electron densities and temperatures of the ejecta. Using Monte
Carlo modeling of the ejecta, we derived the structure, filling factor, and
mass from comparisons of the optical and ultraviolet line profiles.
