> Are there any good indicators for laymen what likely punishments he would have been facing if he would have continued to trial and lost?
For federal crimes, sentencing is generally governed by the federal sentencing guidelines. [1] The application is conceptually simple -- there are guidelines for determining the offense level for each base crime, guidelines for grouping offenses (some of which just keep the most serious, some of which start with the most serious and increase based on other offenses), and guidelines for adjustments to the offense level for various factors such as actual harms inflicted, the defendants criminal history, the defendants acceptance of responsibility, and so forth, and finally guidelines to translate offense level into sentence. But the details are quite involved.
Perhaps the most important thing to note, in the federal guidelines, is that in most cases, where multiple convictions are handed down for offenses involve the same victim and the same act or transaction, or different acts or transaction as part of the same plan or scheme, the offense level is set by the single most serious count alone -- charging multiple counts of the same charge basically just increase the chance of getting a conviction.
For state offenses, sentencing is handled by state-specific rules.
[1] http://www.ussc.gov/Guidelines/2013_Guidelines/index.cfm