Do you think these books would be good resources for starting to learn the language?

Consider the course material for the DysguCymraeg course. You can download it for free or purchase it for £10, plus postage. It’s very good.

Read the wiki on the sub. Physical books alone are not enough. You need to learn how to pronounce words. There is a whole list of free resources in the wiki.

Colloquial Welsh absolutely yes, the best in class. I wouldn't trust a language learning book that promises you that no grammar study is required on the other one.

Colloquial Welsh is great, as is everything else by Gareth King. There are loads of other resources you can use too, particularly with respect to hearing the language spoken and getting a feel for pronunciation.

• SaySomethingInWelsh is a good audio course which will help with pronunciation but won't teach you grammar - https://app.saysomethingin.com/ - and their forum is here - https://en.forum.saysomethingin.com/c/welsh/5
• SSiW’s old course is free and is here https://en.saysomethingin.com/welsh/level1/intro 
• LearnWelsh has lots of online or in person courses, many of them free, (all of them free if you're under 25): https://learnwelsh.cymru/
• City Lit in London has a small selection of online and in-person courses https://www.citylit.ac.uk/courses/languages/celtic/welsh  
• The Open University has a short course for beginners that’s free: https://www.open.edu/openlearn/languages/welsh/croeso-beginners-welsh/ 
• BBC Bitesize has Welsh as a Second Language materials available for free https://www.bbc.co.uk/bitesize/subjects/z8qmhyc 
• The old BBC Catchphrase course is still available: https://www.bbc.co.uk/wales/catchphrase/catchphrase1/lessons1.shtml 

I run two websites for learners: 

• Ymestyn is a new program of structured practice for intermediate learners: https://ymestyn.cymru/
• ClwbMaluCachu is a basic grammar reference resource with tables of conjugations of helper verbs, etc, though I'm still transferring content from the old HTML site. https://clwbmalucachu.co.uk/

Some other books, if you can get hold of them at a reasonable price, that will help: 

• Learner's Dictionary, by Gareth King is really good because it explains usage in more detail. 
• Modern Welsh, by Gareth King absolute stonker of a reference book. 
• BBC Learn Welsh is a really good, if short, grammar book for looking up basics
• Welsh Rules, by Heini Gruffudd is pretty good too

There are loads of YouTube channels, and I listed them here: 

• https://www.reddit.com/r/learnwelsh/comments/1r9rm5t/youtube_channels_for_welsh_learners/

Depending on where you are, there might be a Welsh meet-up near you. Check this map from the Paned website https://paned.cymru/:

• https://www.google.com/maps/d/viewer?mid=12gf3J_4ozjROzhzuUbv_xip5VOfZNyc

Welsh TV, ie S4C, is available from their website or via iPlayer, and almost always has English subtitles, and Welsh subtitles only slightly less often. Some programs are available internationally, the rest just in the UK: 

• All: https://www.s4c.cymru/clic/ 
• Internationally available: https://www.s4c.cymru/clic/Categories/99

There are various Welsh tutors around: 

• Dringo is a new website where you can find and book tutors: https://dringo.org/ 
• Richard Morse: https://www.eventbrite.co.uk/o/richard-morse-17295683185
• Doctor Cymraeg aka Stephen Rule: https://doctorcymraeg.wales/

There are lots of podcasts in Welsh, though the best two for Welsh learners imho are Sgwrsio and Hefyd. Also lots of stuff on BBC Sounds (UK-only), and, of course, BBC Radio Cymru: 

• Podcast directory: https://ypod.cymru/
• Sgwrsio archives: https://ypod.cymru/pods/podlediad/sgwrsio 
  • New Sgwrsio episodes are mixed up with the rest of the BBC’s learner’s podcast https://www.bbc.co.uk/sounds/series/p02nrvyj 
• Hefyd: https://richardnosworthy.wales/podcast/
• BBC Sounds: https://www.bbc.co.uk/sounds/search?q=cymraeg
• BBC Radio Cymru: https://www.bbc.co.uk/sounds/play/live/bbc_radio_cymru
• BBC Radio Cymru 2: https://www.bbc.co.uk/sounds/play/live/bbc_radio_cymru_2

For Americans, there’s also the Madog Center for Welsh Studies: 

• https://www.rio.edu/campus-life/campus-facilities/madog-center-welsh-studies/welsh-language-classes

Everyone’s given good answers about additional courses etc.

I’d say try colloquial Welsh. It’s a great book, also comes with a ton of MP3s you can listen to to learn how it should sound.

Also try the app called ‘say something jn’ they have a Welsh course that’s really good.

I bought the Colloquial Welsh and struggled with it as an absolute beginner. That isn't a criticism of the book, different methods suit different people. I then decided to sign up for online lessons with Dysgu Cymraeg (Learn Welsh), and I'm now into my second year (South Welsh). What I like are all the different resources that come with it - free coursebook, free audio, free online course etc. I'm also doing the Memrise course because it has lots of little videos for each level along with common expressions.

The Colloquial language books are generally fantastic and have taught me other languages in the past. This Welsh one is no exception. I can only recommend Colloquial Welsh, as I have never heard about Welsh without Worry before - and neither have anyone else apparently judging by these answers.

For some listening and speaking practice alongside the books, there’s a free beginner series here: first Welsh lesson. It uses northern Welsh, with English explanations and practice material linked in the description.