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However, IGB will not instantly start loading the data into the display. 

When you open files, IGB adds them to the list of opened files in the Load Mode table Data Management table in the Data Access tab.  . Note that the Data Management table lists a Load Mode for each opened file or data set. By default, IGB adds most files and data sets using the Region in View load mode. Data sets and files with load mode Region in View will load into the main data display when you click the Load Data button. To display data from these files, zoom in to a region you want to see, and click the Refresh click Load Data button. Whatever data in the file that overlaps with the current region in view will appear in the display.

If Tip: If your data file is not large, it's probably best to set the change Load Mode to Whole Genome. If you do that, IGB will load then read and display all the data right awayin the file. Examples of data sets that work best when loaded in the Whole Genome mode include: gene models for the entire human genome or the junctions.bed file created by the TopHat spliced alignment program.significant regions identified in a ChIP-Seq experiment. 

For more about loading files, please see Loading data.

.bam files need a .bai file

IGB can readily display alignments data from .bam files. However, it requires a .bam index file (called a .bai) to be present in the same folder as the .bam file.

I opened my sequence file (".fasta" or ".bnib" or "twobit") but all I see is a gray bar and dashes.

When you open a "fasta" (or other sequence) file, and if you have not already selected a species and genome, then IGB will read the file and construct a new genome, using the names of the sequences it finds in the file.

However, to To save memory, IGB doesn't load sequence data until you click the Refresh Data Load Sequence button. To view the bases, click the Refresh Data button and then zoom in.

If you have opened a sequence file, but not refreshed it, when you zoom in you will see a gray bar with dashes, indicating the sequence bases has not yet been added to the display.

If you have already refreshed your data, then when you zoom in for a closer look, you'll see color-coded sequence bases. By default, IGB uses warmer colors to represent G's and C's and cooler colors to depict A's and T's. You can change the color scheme if you like by choose File->Preferences->Other Options.

For more about zooming, please see Zooming and ScrollingLoad Sequence button and then zoom in.