a good book to buy for reference is the Rock and Water Garden Expert by Dr D G Hessayon, you should be able to pick one up on ebay for around £2 plus postage.
You don't say how deep your pond is, however, in the main you need oygenating plants, deep water aquatic plants, marginal plants and a few bog plants if you have a muddy bit on the edge.
I have one medium lily - frogs love sitting on the pads, 1 water hawthorn - gorgeous and fragrant , 1 golden club and one arum lily - great for emergents - as deep plants, very good mix.
As marginals I have water forget me nots, pickerel weed, carex, flag and iris, kingcup, juncus. Can't remember what oxygenators I have altogether but if you look at djackso's list the unwanted pests are included there, tho I do have curly pondweed and the insects etc love that. I'm sure there's more but just came in from work so no brain
