You can use block libraries and tool palettes to organize and manage blocks.
A block library is a collection of block definitions stored in a single drawing file. You can use block libraries supplied by Autodesk or other vendors or create your own.
You can organize a set of related block definitions by creating the blocks in the same drawing file. Drawing files used this way are called block, or symbol, libraries. These block definitions can be inserted individually into any drawing. Block library drawings are not different from other drawing files except in how they are used.
When you define a block in the block library drawing (using BLOCK), you can include a short description of the block.
You can also creating a visual index of each block definition by inserting it in the library drawing and including text that provides the block name, the date of creation, the date of the last modification, and any special instructions or conventions.
Use DesignCenter to view and copy block definitions individually from block library drawings (or from any existing drawing) to your current drawing. DesignCenter does not overwrite an existing block definition in a drawing with one that comes from another drawing.
Once you've added a block tool to a tool palette, you can insert the block reference by dragging it from the tool palette to the drawing or by clicking and placing it in the drawing.