Single Sound Source (CV)
The basics, CV. A basic CV reclist should contain all necessary sounds plus some extras that enhance the voicebank. The links below this are to CV reclists. The first link sends you to a Japanese page if you are on Chrome have it translate the site into your language. The second link is to 2 basic CV lists by YukitoYuki.
Hiragana Lists: https://www45.atwiki.jp/vbmaker/pages/18.html
Romaji Lists: https://sta.sh/02bhdm2g0w43 and https://sta.sh/0etmhkj2xz0
Continuous Sound Source (VCV)
Continuous sound sources or better known as VCV is a smoother way to record. It is recommended for intermediate and advanced users. You can record to BGM or some other rhythm of consistency, metronome, beats. I recommend 90-140 bpm BGM (although tempos such as 60 and 200 have purposeful uses ). You also can OREMO to record and SetParam to oto or use a mobile device or other recording software to record or use OREMO's built-in oto calculator for Hiragana lists. You may also use Moresampler's oto gen which both encodes in Hiragana and romaji or UTAU or UTAU-Synth's oto editor. The BGM I'm linking you to is 120 (in BGM section), although you MAY be used to VCCV's BGM do not intake before the recording. In setparam when it appears click the auto estimation, set recording tempo to 120 and set utterance start to 2 and set msec. to beat. THIS IS NOT THE FINAL OTO, YOU MUST EDIT THIS.
Romaji 7 mora: https://sta.sh/025ksl2o0oub
Hiragana Lists 1: https://www45.atwiki.jp/vbmaker/pages/13.html
Tatsumi's 6, 7, and 8 mora: http://ch.nicovideo.jp/tatsu3/blomaga/ar426004
CVVC is a mixture of CV and VC. CV otoing skills are needed but, VC skills are still needed. Does not need 1 vowel 1 consonant though, and languages more complicated such as English have CCV such as "sta" and "kle" are considered as CV.
Tatsumi's lightweight lists: http://ch.nicovideo.jp/tatsu3/blomaga/ar598480
Delta Lists: http://ch.nicovideo.jp/delta_kimigatame/blomaga/ar477842
Edited Tatsumi 6 mora: https://drive.google.com/file/d/0B2c27jh2XUlVX0R1UkR3UG1Dd00/view?usp=sharing
Recording BGM differs from person to person. I prefer Maiko's 7-8 mora BGM. Some may like OneNoteJazz.
Maiko's BGM's: https://onedrive.live.com/?cid=c2bdab8f8776d50c&id=C2BDAB8F8776D50C!1270&ithint=folder,&authkey=!APOlA5OON9P3tqs
Other BGM's(There were too many, just check these for the mora that you need ranges from 1-12): https://www45.atwiki.jp/vbmaker/pages/26.html
That's about it, I'me Yanderu signing off. (Also I may make an oto resource but, if I feel they're not appropriate enough). Or maybe base VCV Oto's. Thank you @Kiyoteru for the corrections of misleading information and corrections on some things I went wrong on! All things in red besides this message are corrections that Kiyoteru has corrected.