I am also a hooker, and I actually followed a conditioning programme with my clubs senior first XV from may till about mid july so I can't help you with that. Really just that you should work in blocks. For example, we spent 3 weeks on general conditioning, getting people back into the way of training, then another 3 on speed developments, then a tougher conditioning programme, then some agillity then rugby specific conditioning (IE rucking constnantly for 4 minutes or something like that).
As for gym work, I was in for 3 sessions a week. I split my exercises into upper and lower body.
First session a week was spent doing bench press, shoulder press, shrugs, bent over arm row and flies and squats (a lower body exercise, I know, but as a front row I think that working your lower body with an excerise such as squats is essential).
Second session was lower body. So dead lift, squats, lunges, step ups. Not as many exercises because you will lift alot more weight on your legs and I did not want to over do it on my back.
Third session, usually on a saturday, was more of a mix and slightly lighter, again, as not to over do it. Usually it was squats, bench, shoulder press, shrugs and lunges.
During each gym session I worked my core. This is absolultey essential to any rugby player but especially a front row. I would do sit ups, leg raises (lying on a bench with my legs over the edge and raising and lowering my legs very slowly), planks with a medicine ball (feet on it...this seems to work it more), press ups with my legs on the ball and another kind of press up where by you go down, then up then when up move one of your arms up.
Thats what I used, and this is bearing in mind that even though I'm only 17, I am 15.5stone and have been using weights since I was 14. As I've said, I'm quite big lad with alot more muscle on me than most folk my age. If you have never really done proper gym work before, this probably is not for you.