Long-handled shears are made by nearly all the garden tool companies and you'll find a good range available.

Some have blades at right angles to the handle, for trimming tall grass. Most have blades in line with the handles, designed for you to tidy up lawn edges (best done after every mowing session so that the clippings can drop and shrivel unobtrusively), the main points to look for are appropriate handle length, blade length, and weight. Ideally you should be able to edge your lawn while standing upright, not stooping over and getting backache. Shorter blade versions are better for curving lawn edges and are lighter too.

Some gardeners hate lawn edging because they make it hard work for themselves - by opening and closing both handles as if using loppers. A more efficient technique is to hold one handle still (the one connected to the lower blade) and just move the handle connected to the upper blade in order to snip through the grass. Try it and see - it's faster and less tiring.