I went though a period when I decided I was gonna start taking pictures of flowers, but then I realised I was being a right pansy. However, I still absolutely love
this picture however un-masculine that makes me.
Anyway that's what inspired me to make myself broke by buying a 100mm macro lens - seeing awesome close ups of flowers and wanting to do them myself. I don't take pics of flowers with it anymore, I use it for everything as it's so bloody sharp and useful for looking at stuff really close-up.
I'd definitely recommend getting a 100ish-mm macro and a film SLR to start with, then move up to a digital SLR. The reason I say this is because a film SLR and a lens is gonna cost you beans compared to a digital SLR + macro lens. You can always sell it on eBay if you decide to get a digital SLR later as well.
Good to see you have a tripod as you'll bloody need it. Try getting a non-blurred flower using ISO 50 Fuji Velvia at f/4 on an overcast day in the shade while the wind's blowing ffs

it can be hard enough *with* the tripod...
Anyway once you've got the slr and the macro lens, you might want to get a reflector as this can make the lighting softer or more interesting. The reflector can be useful to help block the wind on a windy day, helping to stop flower heads blowing about...
Perhaps think about getting a flash that you can use off-camera such as a Metz 45-CL4, you can pick one up in decent condition for about 70 quid secondhand, to add interesting highights to your subject.
So there you go...
35mm SLR
100mm Macro lens
loads of Fuji Velvia 50 or 100
Tripod
Reflector
Flash