Without knowing how many scart connections your tv has this is difficult to answer. Try this connection wizard for starters.
http://www.dtg.org.uk/consumer/connection_wiza rd.html
I'd keep it simple and have a viewing setup that works such as :-
Aerial in & out of dvdr into tv
Scart out of dvd to tv (gives better pic quality for watching dvds)
Then when you need to dub vhs I'd connect the vcr to the dvd scart in. You should be able to see and hear what you are dubbing via the dvd.