I pretty much graft all of my apples now from either my stock or local trees. You'll need some grafting tape, grafting wax, and a grafting knife. Make you sure you get an actual grafting knife, its sharpened only on one side. Time is coming up for sure. Scion and rootstock really should be the same size or pretty close but thats not neccessarily a requirement, it will just help to line up both xylems/phloems.I would suggest a whip and tongue graft. I assume your doing apples or pears? Any questions just ask, as I dont have alot of time right now. I would also suggest searching whip and tongue grafts or something like that in youtube, there are actually some videos out there that show how that would be easier than me trying to explain it.