Old English weorc, worc "something done, discrete act performed by someone, action (whether voluntary or required), proceeding, business; that which is made or manufactured, products of labor," also "physical labor, toil; skilled trade, craft, or occupation; opportunity of expending labor in some useful or remunerative way;" also "military fortification." This is from Proto-Germanic *werka- "work" (source also of Old Saxon, Old Frisian, Dutch werk, Old Norse verk, Middle Dutch warc, Old High German werah, German Werk, Gothic gawaurki), from PIE *werg-o-, a suffixed form of the root *werg- "to do."
The meaning "physical effort, exertion" is from c. 1200; that of "scholarly labor" or its productions is from c. 1200; the meaning "artistic labor" or its productions is from c. 1200. The sense of "labor as a measurable commodity" is from c. 1300. The meaning "embroidery, stitchery, needlepoint" is from late 14c.
Work of art attested by 1774 as "artistic creation," earlier (1728) "artifice, production of humans (as opposed to nature)." Work ethic recorded from 1959. To be out of work "unemployed" is from 1590s. To make clean work of is from c. 1300; to make short work of is from 1640s.
Proverbial expression many hands make light work is from c. 1300. To have (one's) work cut out for one is from 1610s; to have it prepared and prescribed, hence, to have all one can handle. Work in progress is from 1930 in a general sense, earlier as a specific term in accountancy and parliamentary procedure.
Work is less boring than amusing oneself. [Baudelaire, "Mon Coeur mis a nu," 1862]
book n.
Middle English bok, from Old English boc "book, writing, written document," generally referred (despite phonetic difficulties) to Proto-Germanic *bōk(ō)-, from *bokiz "beech" (source also of German Buch "book" Buche "beech;" see beech), the notion being of beechwood tablets on which runes were inscribed; but it may be from the tree itself (people still carve initials in them).
Latin and Sanskrit also have words for "writing" that are based on tree names ("birch" and "ash," respectively). And compare French livre "book," from Latin librum, originally "the inner bark of trees" (see library).
The sense gradually narrowed by early Middle English to "a written work covering many pages fastened together and bound," also "a literary composition" in any form, of however many volumes. Later also "bound pages," whether written on or not. In 19c. it also could mean "a magazine;" in 20c., a telephone directory.
The use of books or written charters was introduced in Anglo-Saxon times by the ecclesiastics, as affording more permanent and satisfactory evidence of a grant or conveyance of land than the symbolical or actual delivery of possession before witnesses, which was the method then in vogue. [Century Dictionary]
From c. 1200 as "a main subdivision of a larger work." The meaning "libretto of an opera" is from 1768. A betting book "record of bets made" is from 1812. The meaning "sum of criminal charges" is from 1926, hence slang phrase throw the book at (1932). Book of Life "the roll of those chosen for eternal life" is from mid-14c. Book of the month is from 1926. To do something by the book "according to the rules" is from 1590s.