Hi there , your book needs binning !! You should always emulsion first,after you have prepared the woodwork ( sanding down,filling, caulking etc)then cutting in around the woodwork as neatly as possible, then roller the walls with your emulsion. When the emulsion is dry ,apply undercoat and when dry apply gloss. You do need a steady hand to do this , but after a while you will get the hang of it. As Zebuk says , your gloss brush should be a sensible size i.e 1 and ahalf or 2 inch ,but no bigger and it will get easier once you get the hang of it. I have been a decorator for 24 years and this is not only the right way but it will give you the best finish if you take your time and don't rush. Good luck.