Across:
8 Her work is bound to be read (AUTHOR) by bookseller (AUTHOR),
9 Leaders of revolutionary insurgency locked (leaders of ‘Revolutionary Insurgency Locked’ = -RIL-) in unstable (= anagram indicator) Alamo (Alamo = AMA-LO) (AMARILLO) from city in Texas (AMARILLO),
10 Knocking back (= reverse indicator) containers (pots = STOP) of Scotch? (scotch/put an end to = STOP),
11 Couple of views (eye + witness = EYEWITNESS) in The Observer? (EYEWITNESS),
12 Picture (DEPICT) cited (cited) novel (= anagram indicator) (cited = DE-ICT) about president (-P-) (DEPICT),
14 Describes (PORTRAYS) something similar in 12 across (‘depict’ = PORTRAY-) at school (-S) (PORTRAYS),
15 Instrument (WHISTLE) to put an end to (-STOP) 24 across (‘tour’ = TOUR) (WHISTLE-STOP TOUR) with brief visits (WHISTLE-STOP TOUR),
18 Better (better) off (= anagram indicator) (better = BR-ETTE) including a French (a = -UN-) (BRUNETTE) woman with dark hair (BRUNETTE),
20 Teenagers set off (‘teenagers’ ‘set’ off/ without ‘set’ = enager = ENRAGE) to get someone’s goat (ENRAGE),
22 Went around like a fan (OSCILLATED) with a cellist – do (a cellist do) play? (= anagram indicator) (a cellist do = OSCILLATED),
24 To be sure to release bees (‘to be sure’ to release ‘bees’ = tour = TOUR) for the visitors to take? (TOUR),
25 Leo, for one (SIGN-), gets to put something in the letterbox (-POST) (SIGNPOST) with guide (SIGNPOST),
26 Knocks over (= reversal indicator) container (pan = NAP-) with the French (‘the’ French = -LES) (NAPLES) port? (NAPLES).
Down:
1 Slow type (TURTLE) comes out of his shell every so often (TURTLE),
2 Crafty type (SHIP) of hot (-H-) drink (sip = S-IP) outside (SHIP),
3 Relation (relation) travelling (= anagram indicator) (relation = ORIENTAL) from the East (ORIENTAL),
4 Martin leaves Parliament (‘Martin’ leaves ‘Parliament’ = pale = PALE) as white as a sheet (PALE),
5 A vicar (a vicar) prepared (= anagram indicator) (a vicar = CAVIAR) a fancy spread (a fancy spread = CAVIAR),
6 Makes a name for one of those on the board (SIGNWRITER) with warning (SIGN-) to bookmaker (-WRITER) (SIGNWRITER),
7 What father might do (BLESS YOU) for open burger (open ‘Burger’ = B-) from Takeaway (-LESS) with lamb (ewe) reportedly (= homophone indicator) (‘ewe’ = ‘YOU) (BLESS YOU),
13 Is incapable of feeling (INSENTIENT) popular (IN-) and responsive (-SENTIENT) (INSENTIENT),
14 No longer in (PASSÉ) passages releasing gas (‘passages’ releasing ‘gas’ = pases = PASSÉ),
16 Economic misfortune (HARDSHIP) for firm (HARD-) getting 2 down (‘ship’ = -SHIP) (HARDSHIP),
17 A bit much (OVERDONE) from ring (O-) leader of the Mafia (Don = -DON-) following (= position indicator) father (Rev) back (= reverse indicator) (Rev = -VER-) from Spain (-E) (OVERDONE),
19 Short (e) plucky type (lute) (‘lute’ without ‘e’ = lut) retires (= reveres indicator) (lut = TUL-) to flat (-LOW) (TULLOW) part of Carlow (TULLOW),
21 Estimates (GAUGES), over and around, for example (e.g. = G-E-), part of the summer (August = -AUG-) season opening (‘Season’ opening = -S) (GAUGES),
23 Counts (TOTS) bank’s toxic assets (banks ‘TOxic asseTS’ = TOTS),
24 Some lose patience (some ‘losE PATience’ = epat) going back over (= reverse indicator) (epat = TAPE) recording (TAPE).