Stu, I assume the bike was last registered in the UK, if so this makes life simpler as you dont need to obtain proof that VAT has been paid if it was an import.
Also are you close to a DVLA center? If so I would pop in and have a word, I found them very helpfull but differant people did give me differing advice. Try, if possible, to deal with the same person.
Insure the bike via the frame number. Ask if there is a time limit on this....they will issue you a cover note but some insurers (Im with Bennetts) wont give more than one months cover on a frame number...this caused me no end of hassle.
Pre book your MOT and you can ride the bike to the testing station.
Take your V55/5, insurance cert, MOT, dating cert (I also needed proof of ID as my bike had an imported frame, check if you need this, I'm pretty certain you do) to the DVLA office. You will need £55 for the registration, road tax will be free). They will then arrange a date for inspection. This is not any sort of "MOT" test, just to confirm the bike is what it says it is on the paperwork. I have heard that some centers dont do this inspection, in which case your in luck and will get all your relevant paperwork there and then. This is why I would have a word with them first and try and deal with the same person. Getting in touch with a local office isnt easy...there are no direct numbers or email addresses, you have to ring up Swansea and arrange for the local office to contact you.