What is the camera capable of shooting? Maybe give us the model number and age of the camera?!

Standard DVDs (DVD-R or DVD+R)are only capable of resolutions of up to 720p I thought. So even if the camera was able to shoot 1920x1080 - on the DVD that you would burn with PD - the DVD will only have 720p visibility... (at least I believe this is the case - please... anyone - if this is NOT correct - CHIME IN... lol)

BD-R discs require an optical burner hardware - but then you can burn to BD-R discs which will allow you to burn 1080p and even higher resolutions I think. But your computer has to have a BD (Blu Ray Disc) capable drive to burn the BD-R discs.

CS PD13 Ultimate - Build 3516, WIN 8.1, 64 Bit, 16G RAM, Intel Core i5 4460, CPU @ 3.2GHz, NVIDIA GeForce GT720, Graphics Memory(total avail.)-4093MB
LG WH14NS40 Blu-Ray Drive

The camera is a Sony HDR-CX900. I need to stay rather vanilla with the disk, the audience are seniors with all kinds of DVD players. My 80 year old sister teaches Tai Chi and this would be for her students, not commercial.

OK, now what model and make of player will they play this DVD on?

We can't anticipate all combinations of players and cameras but if it is a fairly recent model DVD player, then we should be able to suggest some Burn to disk profiles - probably some standards ones even that should all ow the player to play back what you burn.

CS

Edit-Add:
So it looks like the camera is capable of 1920x1080p 60fps - that is a really good capture spec but the 60p will allow a little better looking - fluid motion if there is any 'fast-ish' motion happening.

Your camera Specs: (per http://www.sony.com/electronics/handycam-camcorders/hdr-cx900/specifications)
AVCHD: 1920 x 1080 / 60 p (PS), 24 p (FX, FH), 60i (FX, FH), 1440 x 1080 / 60i (HQ,LP), MP4: 1280x720 30p, XAVC S HD: 1920 x 1080 / 60 P, 30 P, 24 P

Now in Tai-Chi - I don't think there is so you might be able to get away with a 30 fps capture if that is offered with the camera. I don't know if you've seen video shot at 30 fps versus 60 fps - but if you see them side by side - the difference is obvious. But like I stated, you may be able to get away with 30 fps as the subjects are not moving so fast. Your call!

But you need to know if they will be watching this on a Blu Ray player or just a standard DVD player. THAT will present you with a choice if they do. Do you WANT to shoot in HD or not? 1920x1080 will take more file size ... more memory.. and then the processing (rendering and such) may take longer as a result. But the final product - the 1920x1080 versus the 1280x720 (is it 1280?) Standard DVD resolution format - it is obvious which one looks sharper.

So you need to decide - but you did state "... all kinds of DVD players." - THAT would lead me toward the standard DVD profiles for burning. In the Create Disc room(tab) - DVD video - MPEG-2 - Widescreen - HQ - Highest Quality. That is a good quality choice for a Standard DVD - DVD-R and such.

I'm using PD13 so - depends on what version you are using - but in PD13 there really is not much wiggle room - this is the main choice for burning a 4.7 GB DVD-R.

CS (again) PD13 Ultimate - Build 3516, WIN 8.1, 64 Bit, 16G RAM, Intel Core i5 4460, CPU @ 3.2GHz, NVIDIA GeForce GT720, Graphics Memory(total avail.)-4093MB
LG WH14NS40 Blu-Ray Drive