1diff --git a/README.md b/README.md
  2index 5d9c4db..1e6600d 100644
  3--- a/README.md
  4+++ b/README.md
  5@@ -4,8 +4,9 @@ TypeScript implementation of a spreadsheet.
  6 ## TODO
  7 Things I should do.
  8 
  9-### Write documentation for Cell
 10-
 11 ### Write documentation for Sheet
 12 
 13-### Write documentation for Matrix
 14\ No newline at end of file
 15+### Write documentation for Matrix
 16+
 17+### Cell.error should not be of type any
 18+Errors should have specific types so we can have type safety when passing them.
 19\ No newline at end of file
 20diff --git a/src/Cell.ts b/src/Cell.ts
 21index e3986f4..68d0c88 100644
 22--- a/src/Cell.ts
 23+++ b/src/Cell.ts
 24@@ -1,3 +1,7 @@
 25+/**
 26+ * Cell represents a cell in the spreadsheet. It contains a nullable formula, and a value, which is not nullable unless
 27+ * the parsing of the formula results in an error.
 28+ */
 29 class Cell {
 30   private formula: string;
 31   private value: string;
 32@@ -6,6 +10,11 @@ class Cell {
 33   private id: string;
 34   private row: number;
 35   private col: number;
 36+
 37+  /**
 38+   * Creates an empty cell with an id.
 39+   * @param id key of the cell in A1-format.
 40+   */
 41   constructor(id: string) {
 42     var key = parseKey(id);
 43 
 44@@ -17,6 +26,11 @@ class Cell {
 45     this.row = key.y;
 46     this.col = key.x;
 47   }
 48+
 49+  /**
 50+   * Update this cell's dependencies, where `dependencies` is a unique list of A1-format cell IDs.
 51+   * @param dependencies to merge with existing dependencies.
 52+   */
 53   updateDependencies(dependencies: Array<string>) {
 54     for (var index in dependencies) {
 55       if (this.dependencies.indexOf(dependencies[index]) === -1) {
 56@@ -24,42 +38,105 @@ class Cell {
 57       }
 58     }
 59   }
 60+
 61+  /**
 62+   * Return a list of dependencies in A1-format cell IDs, in no particular order, but likely in order of occurrence in
 63+   * formula.
 64+   * @returns {Array<string>} list of dependencies in A1-format
 65+   */
 66   getDependencies() : Array<string> {
 67     return this.dependencies;
 68   }
 69+
 70+  /**
 71+   * Return the zero-indexed column number of this cell.
 72+   * @returns {number} column
 73+   */
 74   getColumn() : number {
 75     return this.col;
 76   }
 77+
 78+  /**
 79+   * Return the zero-indexed row number of this cell.
 80+   * @returns {number} row
 81+   */
 82   getRow() : number {
 83     return this.row;
 84   }
 85+
 86+  /**
 87+   * Get the A1-format ID of this cell.
 88+   * @returns {string} cell ID
 89+   */
 90   getId() : string {
 91     return this.id;
 92   }
 93+
 94+  /**
 95+   * Set the formula of this cell.
 96+   * @param formula to set.
 97+   */
 98   setFormula(formula: string) {
 99     this.formula = formula;
100   }
101+
102+  /**
103+   * Get the formula of this cell if set. Defaults to null, so could return null.
104+   * @returns {string} formula of this cell, if set. Nullable.
105+   */
106   getFormula() : string {
107     return this.formula;
108   }
109+
110+  /**
111+   * Set the value of this cell. If this cell has a primitive value (does not contain a formula), it could be set to a
112+   * value while the formula field is still null.
113+   * @param value to set
114+   */
115   setValue(value: string) {
116     this.value = value;
117   }
118+
119+  /**
120+   * Get the value of this cell. Since value could be null do to an error in the formula, this could return null.
121+   * @returns {string}
122+   */
123   getValue() : string {
124     return this.value;
125   }
126+
127+  /**
128+   * Set error for this cell. Usually in the case of a parse error when parsing the formula.
129+   * @param error to set.
130+   */
131   setError(error: any) {
132     this.error = error;
133   }
134+
135+  /**
136+   * Get the error for this cell. If the formula is parsed properly, or is null, this could be null.
137+   * @returns {any} error to return, could be Null.
138+   */
139   getError() : any {
140     return this.error;
141   }
142+
143+  /**
144+   * Get the renderable value for this cell, meaning the value that is the most meaningful to the user. If the error is
145+   * null, we return the error. If we don't have an error, return the value.
146+   * @returns {string} renderable string value to return.
147+   */
148   getRenderedValue() : string {
149     if (this.error !== null) {
150-      return this.value;
151+      return this.value.toString();
152     }
153-    return this.error.toString()
154+    return this.error.toString();
155   }
156+
157+  /**
158+   * Returns the human-readable string representation of this cell, omitting some obvious fields.
159+   * @returns {string} to return
160+   */
161   toString() : string {
162     return "id=" + this.id + ", value=" + this.value + ", formula=" + this.formula + ", error=" + this.error;
163   }