Theme: Make your Bed - Items found on a bed.
17A. Linus' trademark in "Peanuts" comics : SECURITY BLANKET
27A. 1959 Hudson/Day film : PILLOW TALK
48A. Song publisher's output : SHEET MUSIC
63A. Waistline concern : MIDDLE-AGE SPREAD
Argyle here. I believe this may be a debut puzzle. An oddment is the two grid-spanners have their theme word at the end while two shorter ones begin with a theme word. The fill is good. On the whole, a fine Monday. Missing: {J,Z)
Across:
1. NetZero and AOL : ISPs. (Internet Service Provider)
5. Winter precipitation : SNOW
9. "Poison" plant : SUMAC
14. NBAer O'Neal : SHAQ
15. Classic film character whose last word was "Rosebud" : KANE. (Citizen Kane, 1941)
16. "The Devil Wears __" : PRADA. Novel and movie(2006).
20. Bone: Pref. : OSTEO
21. U-shaped river bend : OX-BOW. (The Ox-Bow Incident (1943))
22. USN rank : ENS. (Ensign)
23. NYC dance troupe : ABT. (American Ballet Theatre, usually a later in the week entry)
25. Daunting duty : ONUS
33. Emulated Michael Phelps : SWAM. I may not sink but I couldn't emulate! 51D. Olympians' dreams : GOLDS
36. School subj. with a lab : SCI.
37. Link with : TIE TO
38. Stable newborns : FOALS
39. Chatter : YAK
40. Mistaken : IN ERROR
42. Wine, on le menu : VIN. Vino on il menù or el menù.
43. Increasing in vol., musically : CRESC. (crescendo)
45. __ firma : TERRA. (solid earth)
46. Decline : EBB
47. Rope material : HEMP
50. Othello's confidant : IAGO. Shakespeare's bad guy and a crossword mainstay.
52. Barnyard clucker : HEN
53. Former Texas governor Richards : ANN. Played herself on "King of the Hill".
55. Church keyboard : ORGAN. Somewhat odd clue.
59. Say : UTTER
66. Without a break : ON END
67. "Not a problem" : "SURE"
68. Sky bear : URSA
69. Fizzy fountain drinks : SODAS
70. Lowly laborer : PEON
71. CPR pros : EMTs. (Cardiopulmonary resuscitation/Emergency medical technician)
Down:
1. "That __ last week!" : IS SO
2. Females : SHEs
3. War-ending agreement : PACT
4. Rat on the gang : SQUEAL
5. Hit the slopes : SKI
6. Belg.-based peacekeeping gp. : NATO. (North Atlantic Treaty Organization)
7. Black stone : ONYX
8. Jack who played Sgt. Joe Friday : WEBB
9. Breed, as salmon : SPAWN
10. Keats' Grecian vase : URN
11. Disturbs the status quo : MAKES WAVES
12. Port in Yemen : ADEN
13. Litter box users : CATS
18. Like some high-tech machines : ROBOTIC
19. Search (for) : LOOK
24. Bed with a mate : TWIN
26. GI show gp. : USO. (United Service Organizations)
27. TV show about a consultant thought to have ESP : "PSYCH". On USA Network Original Series.
28. "As if __!" : I CARE
29. Having similar opinions : LIKE-MINDED
30. Canines and molars : TEETH
31. "But only God can make __": Kilmer : A TREE
32. "The Maltese Falcon" actor Peter : LORRE. (1941)
34. Suspect's story : ALIBI
35. "Hardball" airer : MS NBC
38. Case of false incrimination : FRAME-UP
41. Surg. branch : ORTH. (orthopedics)
44. Restful retreat : SPA
48. Achy : SORE
49. False : UNTRUE
53. "Famous" cookie guy : AMOS
54. Chile boy : NIÑO
56. Surprised sound : [GASP!]
57. Fluish feeling : AGUE
58. Wolfe of detective fiction : NERO
60. Time in office : TERM
61. Sunrise direction : EAST
62. Nutritional stds. : RDAs. (Recommended Dietary Allowances)
64. Forensic ID : DNA. (deoxyribonucleic acid)
65. D.C. bigwig : SEN. (senator)
My bed's made, now I'll go lie in it.
Argyle