There are some good recent books on the Merovingian Franks (and Charlemagne), but the main problem is that the majority of such recent scholarships has been written either in German or in French. Not so many Anglophone scholars write books on this topic, especially for general readers. There are still certain good books also in English, but they are often very expensive and not-so-easy read for non-specialists like me.

• Fouracre, Paul. The Age of Charles Martel. London: Longman (Routledge), 2000.
• Nelson, Janet L. King and Emperor: A New Life of Charlemagne. Harmondsworth: Penguin, 2019.
• Wickham, Chris. The Inheritance of Rome. Harmondsworth: Penguin, 2009. Penguin History of Europe.
• Wood, Ian N. The Merovingian Kingdoms, 450-751. London: Longman (Routledge), 1994.

These (especially Wickham's) should be the introductory work for every readers.

Good introductory works on Gregory of Tours and his history of the Franks would be very helpful to understanding the Merovingian Franks, but a companion/ study on him (ed. Alexander C. Murray or that of Heinzelmann) in English are tend to be a bit expensive.

• [Collection of (translated) primary sources in English]: Murray, Alexander C. (ed.). From Roman to Merovingian Gaul: A Reader. Toronto: UTP, 1999.
• [Partial Translation in English]: Murray, Alexander C. (ed.). Gregory of Tours: The Merovingians. Toronto: UTP, 2005.
• Heinzelmann, Martin. Gregory of Tours: History and Society in the Sixth Century, trans. Christopher Carroll. Cambridge: Cambridge UP, 2003.

If you can understand French, I'd also recommend the works by Régine Le Jan, Bruno Dumezil & Alan Dierkins, but I'm sure /u/Libertat can point you to some more interesting as well as readable works in French as well as in English (I also strongly recommend to check [the wiki section of her/his previous answers in this subreddit] (https://www.reddit.com/r/AskHistorians/wiki/profiles/libertat).

As for the documentary on the Franks, my first recommendation is: The Germans: Charlemagne and the Saxons (2010: ZDF- DW).

[edited]: fixes typos.

• Before France and Germany: The Creation and Transformation of the Merovingian World; Patrick J. Geary; Oxford University Press; 1988
• The Frankish Kingdoms under the Carolingians (751-987) by R. McKitterick; Londres-New York : Longman; 1983
• The Merovingian Kingdoms,450-751; Ian Wood; Longman; 1994

These are probably the best available introductory books on the matter in English : they have a mostly chronological approach so you can have a broad view of the Frankish realm between the Vth and the IXth centuries. They're not that recent however, and can be well completed by reading studies about the broader Late Ancient period, for instance Walter Goffart's Barbarian Tides or Guy Halsall's Barbarian Migrations and the Roman West.

A good part of the recent publication on Franks was written, for pretty much obvious reasons, in French and German alongside English : unfortunately, translations are uncommon so being fluent enough in one or both of these languages is a plus.

If it's the case, I'd strongly suggest these introductory books

• Des Gaulois aux Carolingiens; Bruno Dumézil: Presses Universitaires de France; 2013 - available in audiobook
• La France avant la France (488-888); Geneviève Bührer-Thierry, Charles Mériaux; 2009
• La Naissance de la France : les royaumes francs (Ve-VIIe siècles); Charles Mériaux;Belin; 2014.
• Histoire des Carolingiens; Isaïa M.-C.; Seuil; 2014

An hotch-potch of advisable recent publications could include,besides what u/y_sengaku posted :

• [Bishops and the Politics of Patronage in Merovingian Gaul; Gregory I. Halford; Cornell University Press; 2019]
• [Charlemagne's Early Campaigns (768-777), a diplomatic and military analysis]; Bernard S. Bachrach; Brill; 2013 : this in particular was violently criticized by Guy Halsall, especially the point on the "planning" of early Carolingian campaigns as a reaffirmation of power in the former realm. It's still worth the read as is his Merovingian Military Organization, 481-751**;** Bernard S. Bachrach; University of Minnesota Press; 1972]
• [Economie rurale et société dans l'Europe franque (VIè-IXè siècles);J.-P. Devroey Belin: 2003]
• Les Carolingiens, une famille qui fit l'Europe; Pierre Riché; Pluriel : Hachette; 2012
• [Le Monde Franc et les Vikings, VIIIè - IXè siècle; Pierre Bauduin; Éditions Albin Michel; 2009]
• [Les sociétés occidentales du milieu du VIe à la fin du IXe siècle. Philippe Depreux; Rennes : Presses universitaires de Rennes, 2002]
• [Famille et pouvoir dans le monde franc (VIIe-Xe siècle) : Essai d’anthropologie sociale; Régine Le Jan;. Paris : Éditions de la Sorbonne, 2003 ] alongside [ La Royauté et les élites dans l'Europe Carolingienne; Régine Le Jan (éd.) Lille : Presses de l'Université de Lille]
• [Religious Franks. Religion and power in the Frankish Kingdoms. Studies in honour of Mayke de Jong; Dorin van Espelo (dir.); Manchester University Press ;2016]
• [*Servir l'État Barbare dans la Gaule Franque; Bruno Dumézil; 2012; Éditions Tallandier*] which focuses on the make-up of the Frankish state and administration in Gaul during the early Middle-Ages, describing how it regularily evolved and finally disappeared under Carolingians.
• [Shifting Ethnic Identities in Spain and Gaul, 500-700 : From Romans to Goths and Franks; Erica Buchberger; University of Amsterdam Press; 2017] Although not exclusively looking at the situation and identities in Merovingian Gaul, it still describes the dynamic at work in the northern part and how Frankish identity became predominant.
• [The Age of Charles Martel; Paul Fouracre; Routledge; 2010]
• [The Carolingian Economy; Adrian Verhulst; Cambridge Medieval Textbooks : Cambridge University Press; 2004]
• [The Merovingian Kingdoms and the Mediterranean World: Revisiting the Sources; Stefan Esders; Yitzhak Hen; Pia Lucas; Tamar Rotman; (eds.); Bloomsbury Academic; 2019] are a series of studies displaying the relations between the Frankish realm and the Mediterranean basin it is becoming increasingly clear it was a full part of, culturally and politically.
• *[*The World of Gregory of Tours; Kathleen Mitchell, Ian Wood (editors); Brill: 2002] which, trough the central figure of Gregory of Tours, explores the VIth century in Francia, Gaul and broad late ancient western world.

There's of course the lot of more specialized studies that I can't mention all, especially regional studies either in the Frankish "cores" (Neustria, Austrasia, Burgundy) or its peripheries (Aquitaine, Catalonia, Provence, Italy, Germania, South-East England, Brittany, etc.) : if you're interested on a specific region or topic, do not hesitate to ask for it.

EDIT : As for documentaries : Pr. Paul Freedman uploaded several courses on Early Middle-Ages on Youtube especially 10, 11, 19, 20, 21 on Merovingians and Carolingians.

Bruno Dumézil, if you're fluent in French, made several lectures available on Youtube or Dailymotion : on "Barbarian Invasions" (with a part on early Frankish kingdoms) ,Clovis' faith, Gregory of Tours (together with Sylvie Joye) or Paris and Gaul in the late Vth/early VIth centuries.

Hi there anyone interested in recommending things to OP! While you might have a title to share, this is still a thread on /r/AskHistorians, and we still want the replies here to be to an /r/AskHistorians standard - presumably OP would have asked at /r/history or /r/askreddit if they wanted non-specialist opinion. So give us some indication why the thing you're recommending is valuable, trustworthy, or applicable! Posts that provide no context for why you're recommending a particular podcast/book/novel/documentary/etc, and which aren't backed up by a historian-level knowledge on the accuracy and stance of the piece, will be removed.