Early Observations
Intracluster light was first discovered by Fritz Zwicky of Cal Tech in 1951 in a series of photographic observations of the Coma cluster of galaxies. Most of the astronomers who studied IcL in the 60's and 70's were looking for a solution to the dark matter problem: before IcL was discovered, astronomers had used galaxy dynamics in clusters to deduce that the clusters contained more mass than could be accounted for by the observed light. One solution to this dark matter problem that was proposed some time after Zwicky's unheralded discovery of IcL was that this very faint matter in clusters might provide the missing mass...if there was enough of it.
So a number of astronomers doing surface brightness observations of nearby clusters (esp. Coma) tried to catalog and examine the IcL. Alas, they did not find enough of this faint, diffuse starlight to account for the observed effects of dark matter. They did, however, get a handle on some of the properties of the IcL (esp. Coma's). The points generally agreed upon were that the IcL makes up ~30% of the total cluster luminosity, it is somewhat blue and is extended across much of the cluster.
The 80's and 90's
In the early 80's there was a sort of hiatus in IcL observations. This was possibly due to the fact that photographic surface photometry was reaching its observational limits and that IcL was not as interesting now that it couldn't explain dark matter.
The late 80's and early 90's saw a sudden and dramatic improvement in surface photometry with the introduction of Charge Coupled Devices. These CCD's had a much better dynamic range and greater uniformity across the image. One drawback in CCD photometry was that they covered a smaller section of the sky than photographic plates, thus making it difficult to observe large, nearby clusters (one would have to make a mosaic of several CCD images). Thus, the IcL observations in this time period tended to be of clusters farther away than Coma. Most of these observers found that about 20~40% of the total cluster light was intracluster and that it was often profiled about the central dominant galaxies (if cD's were present).
Recent Developments
Since 1998, a growing number of astronomers have discovered intracluster light that forms large features in the galaxy clusters. Some of these features are shaped as arcs or plumes. Such structures are probably the remains of disrupted galaxies. Other concentrations of IcL look more like fuzzy smudges, and have been described as very faint "starpiles."
Coma cluster with IcL features circled 
Coma Plume (region 1 in first pic)
Coma Smudges (regions 2 and 3 in first pic)