Welcome to the topless club
Preserving and maintaining your roof is very important. I have had open top cars on and off for the last 30 years, but never had a fabric roof until I came into ownership of my SAAB
The products I suggest you'll need are the following:
A firm but soft bristled brush to remove loose dirt and dust
Some decent quality (new/unused) paintbrushes for applying various products
Soft top canvas cleaner -
Renovo products are probably the most well revered
Renovo ultra proofer - for re-proofing the roof
And, if it looks faded you can use Renovo soft top reviver.
Also a good idea to get yourself some low-tack masking tape such as the 3M Scotch blue
All these are freely available from eBay or places like Elite Car Care or The Ultimate Finish
(Make sure when you buy the Renovo products you are NOT buying the stuff for vinyl roofs - bottles and names are similar)
Basically you just give the roof a darned good brushing when it's dry (pay attention to the gutters) then apply the cleaner following the instructions on the bottle, after which you apply the reproofer - again, just follow instructions on the bottle.
My advice is to mask off your glass and bodywork. These products can stain the paint a bit - it does come off, but by masking you will save yourself some considerable work later