The biggest mistake most novice gardeners make is buying too many plants/shrubs etc and planting them too close together. I fell into that trap during my first wave of enthusiasm and finished up having to dig some out at a later date because of overcrowding. I have never purchased a book on gardening so can't recommend one but a good one may help when planting time comes around. Chrimbo is a coming so perhaps one of you family would like to buy you a gardening book
. There are millions to chose from.