Great Slave Lake is the 5th largest lake in North America covering a surface area of 80,000 Kmē. Yellowknife is situated on the west shore of Yellowknife Bay on the north arm of the lake.
It is the varying hydrography of the lake that catches first time visitors off guard. The east arm is located in the Canadian Shield, which is noted by its tall, towering cliffs along the shoreline. These vertical rock faces also contribute to some great depths below, 122 M not being uncommon. It's a little unsettling to be trolling along close to one of these rock faces, and have that depth of water underneath you.
As you get closer to Yellowknife Bay, you're still in shield country, but here the cliffs have given way to sloping rock and shale shorelines. As you move down to the south and western part of the lake, you discover more sedimentation occurring with more recognizable soft shorelines and delta-like areas.
Access and Accommodation
Yellowknife and Great Slave Lake can be accessed by taking Highway 2 north to Peace River via Lesser Slave Lake; then Highway 35 north to the Alberta border. Once you enter into the Northwest Territories take Highway 1 to Enterprise, then Highway 3 to Yellowknife. Note that you will have to take the ferry across the Mackenzie River northwest of Enterprise, so it's advisable to call ahead for the ferry schedule. The distance from Edmonton to Yellowknife is 1,513 Km, making for a long haul; but there are plenty of sightseeing opportunities along the way.
A good variety of hotels, motels, and bed and breakfasts await the traveler in Yellowknife. For the camper, a good number of Territorial Parks are located as close as the immediate outskirts of the city. As well, there are some truly fine restaurants in town; the hospitality and friendliness bringing back memories of the Maritimes.
Equipment and Tackle
Equipment and tackle required to fish Great Slave Lake is simple and straightforward. For Lake trout, a medium to heavy action spinning rod coupled with 15 to 20lb test monofilament line will get you by just fine. For lure selection take several size 00 Len Thompson 'Five of Diamonds' in both red and black diamond colors. Another productive lure is the 'Wolverine Special', available at Wolverine Sporting Goods in Yellowknife.
For Arctic Grayling, a 5 to 6 weight fly rod coupled with a forward taper floating fly line will do the trick quite nicely. Just about any typical fly pattern will work at some time or another, but take a good selection of the following:
Dry Flies
The Muncher is a favorite of Ian James for carp, smallies, more. 
Thoughts of a Chicken Rancher. Doc tells it like it is.