Ah small rivers and chub, one of the greatest loves of my life. I spent 4 years living next to the Warwickshire Leam and in a 2 mile stretch I got to know every chub in it I guess.
This type of fishing means learning real watercraft. Before you even get any tackle go and buy a complete camouflaged set of clothes and learn to crawl on your stomach. If you,ve had army commando training it will be invaluable. Even the sight of a white handkerchief will spook them.
In winter mix up a bucket of mashed bread and hemp. Walk down the river and bait up the obvious spots, deep holes, bends, overhanging willows etc.
Then leave the river for about 2 hours and go back with your tackle.
Use crust from a farmhouse loaf to 8 lb line and a 4 hook. A 10 foot rod is ideal. Go to the spots you have baited, get on your stomach and move into place. You should get a fish within seconds of casting your bait if you havn't spooked them.
Get hold of Tony Miles book Search for big chub. Small river tactics are covered here very well.
Have fun - it's the most exciting from of fishing that I know.