Downloadable chapters from Genetics: Analysis of Genes and Genomes, 8th ed.
by Hartl & Ruvolo [Concise reading to quickly get the very basics of molecular genetics]
More books are available from NCBI Bookshelf.
Some books (including Molecular Biology of the Cell, 3rd ed. by Alberts et al.) are accesible only
using keyword searches.
More online books/tutorials for molecular biology/genetics/genomics