1. INTRODUCTION

2. SAMPLE DESCRIPTION

3. SPECTRAL ENERGY DISTRIBUTIONS
3.1. Data
3.2. Multiplicity and Variability
3.3. Determination of Lbol, Tbol, Spectral Index, and SED Classification

4. MODEL GRID
4.1. Model Parameters
4.2. Model Apertures
4.3. Effect of External Heating

5. FITTING METHOD

6. RESULTS OF THE MODEL FITS
6.1. Quality of the Fits
6.2. Overview of Derived Parameters
6.3. Envelope Parameters for Different SED Classes
6.4. Estimating Parameter Uncertainties

7. DISCUSSION
7.1. Deriving Envelope Parameters from a Model Grid
7.2. Envelope Properties and SED Classes
7.3. The Total Luminosities of Protostars
7.4. Potential Problems with TSC Models

8. CONCLUSIONS