HI
"......how do I combine 2 sequences to make it one for rendering into DVD? "
If you mean sequences as clips then they are simple arranged on the sequence track one after the other.in the order you require.
On the other hand if by sequences you mean two individual previously edited films which you may have saved as VP projects.(.vpj files) you will have to follow a different procedure.
Unfortunately you cannot load a VP project on top of a second VP project and have them one after the other on the sequence track. The second one overwrites the first. If you require both films in an editable form together on the track then you would have to save them first to your PC; a CD or DVD as .avi files (or similar) in this way they can be loaded back into VP, added to the media list as avi clips and dragged to the sequence track in the order you want. You can then (as I mentioned above) add your bookmark between them and save the final combined sequence to DVD.
Alternatively you can edit the two films one after the other from scratch again from their individual clips ,(!) add the bookmark and save to DVD via VP but this would be a lot of work.
For myself where I have several films to save to one disc I have always used a third party DVD maker as mentioned.
Nat