The information below comes from my own personal experience, and from the books that you can find linked to this page. See the routes section for a description of the main route to the summit, or to add your own route.
This is a "Trekking Peak" in the Everest region of Nepal. It is a great first himalayan peak. The route to the summit includes a steep slope and a narrow ridge. Crampons, Ice-axe and ropes are necessary, and it is useful to have a sherpa guide who knows the best part of the ridge to climb. The term "trekking peak" can be misleading as in fact most of 14 or so mountains given this title by the Nepalese government are proper mountaineering propositions.
Eric Shipton's party of 1952 named the mountain Island Peak. In 1983 it was renamed Imja Tse, but even the locals still call it Island Peak.
The mountain was first climbed in 1953 by a team in preparation for the ascent of Everest. Today it is still used by many to prepare for everest or other high peaks in the region. When I climbed it there was a polish expedition who were preparing for Ama Dablam. They never reached the summit of Imja Tse - I wonder if they made it up Ama Dablan!
From Dingboche the mountain doesn't look too impressive, it looks very small next to one of the largest mountain faces in the world: the South Face of Lhotse. However, on close inspection it reveals itself to be an interesting and attractive summit with a highly glaciated West Face rising from the Lhotse Glacier. It has a classically beautiful ridge leading to the summit. The continuation of this ridge, descending south-west, provides part of the normal route of ascent and leads in turn to the South Summit, seen capping the rocky west facet of the mountain when viewed from near Chhukhung.
As well as providing an enjoyable climb the peak also provides some of the most striking scenery in the Khumbu. If the peak can be likened to an island in a glacial sea, then the mainland forms a semicircle of cliffs that rise in the north to the rugged summits of Nuptse (7,879m) Lhotse (8,501m), Lhotse Middle Peak (8,410m), as yet still unclimbed and Lhotse Shar (8,383m). To the east, rising above the frozen waves of the Lhotse Shar Glacier, is Cho Polu (6,734m). beyond which can be seen the red granite mass of Makalu (8,475m). The most impressive view for me, was that of Ama Dablan (click here to see photo).
I climbed it straight after Pokalde which is a day's walk away - have a look at that page too - it is a good peak to acclimatise on.
Fly to Kathmandu (Nepal's Capital) and then walk to Namche Bazaar from the trail head or fly to Lukla (a small air strip high in the mountains, a day's walk from Namche Bazaar.)
You leave the Everest Base Camp Trek at Dingboche and walk up to Chhukung. Then a base camp and/or an advanced base camp can be established between 5300 and 5600 m. I made a base camp at the bottom, near the glacier, and a high camp at 5600m. There are a number of places to pitch a tent below the snowline. See (routes section for more details of the normal route (SE Flank. SW Ridge)
Some people do the climb in a 2 week round trip from Kathmandu. this is probably a lttle rushed for proper acclimatisation. I took 4 weeks to climb this peak and Pokalde, as part of a long trek around the whole area. I hired a guide for 4 days to climb this peak and nearby Pokalde and we met him and our porter at the bottom of Pokalde after doing the walk in on our own. Guides should be hired in Kathmandu .
A note on the Maoist insurgency: check the British Foreign and Commonwealth Office (FCO) website or some other governmental site for the current situation. As far as I gather the Maoists do tend to charge a "tax" on tourists in some rural areas. A SummitPost member has added some useful tips from his recent trip - to read them click on the "more info" link at the top of this section.