Getting started with TH2 amp simulator

Congrats on your children!! Playing electric through an amp sim has made my life as a parent much richer. I'm sure it will help you escape a little too.
 
1. Run the Guitar cable from the guitar to the Focusrite interface (don't mic your own amp).
2. Launch Sonar and insert a single audio track into a new project.
3. Set the input for the audio track (at the bottom of the track inspector) to match the input from your interface that your guitar is plugged into. **tip: you might have to click to turn off the pro channel tab to see where to set the input on your track.
4. Click the Input Echo button on the track so that you can now hear the completely clean sound of your guitar. (If there is a lag between the time you play a note and the time you hear it then reduce the latency on your interface by going to
Preferences > Audio > Playback and Recording and set Driver Mode = Asio.
Preferences > Audio > Driver Settings > Click the Asio Panel button and reduce the buffer size).
5. switch the track inspector to the Pro Channel View by clicking Pro Channel at the top of the track.
6. Drag TH2 from the browser window (Hit B to see it if you can't. TH2 will be under Plugins > Audio FX > VST2 > Overloud) to the Pro Channel.
7. Now when you play a note, you hear it through TH2.
8. Click the Master button at the top left. If you are playing a guitar with single coil pickups (like a strat) select Input = Low. If you are playing a guitar with humbuckers (Les Paul) select input=high.
9. Click the In Lev button at the top left of the TH2 window. This lets you know if TH2 is getting enough signal. Now, I usually let my interface auto set the level for the recording with a good 6 dB of head room. This is less signal than TH2 likes, so I often increase the Gain Nob on the Track inspector until the In Lev is showing in the GOOD range. (This trick means you don't clip and you also get the most out of TH2). (Also, don't forget to turn your guitar all the way up to 10 on the guitar body. No reason not to send a loud signal.)
10. Next click the Tuner button to the right of the In Lev button and tune up.
11. On the right hand side, third button down, click SEARCH.
12. Play the guitar while clicking on the different preset choices. Click Load Sound to import the whole row of presets to the main interface so you can switch between them. Load Variation only replaces the selected individual sound (not the row) with the currently selected sound in the main interface.
 
Advanced trick: Credit to Craig Anderton 
1. Drag the EQ in the pro channel BEFORE the TH2.
2. Enable the EQ and the Low Pass (LP) filter (bottom of the EQ).
3. Set the LP Slope around 12 and slowly bring down the LP Frequency while playing.
... see if this doesn't tame some of the high end stuff created by TH2. TH2 emulates nicer microphones than most of us have. When you record an amp with a cheap mic, it doesn't have all that high end. Doing this can help get sounds more like what you are used to hearing.
 
 ** When Craig Anderton mentions 'Re-Amping' he is describing the technique of recording a guitar direct to an interface and then playing just that signal and sending it to a Real Amplifier and then tweaking that amplifier and recording it with microphones. This is somewhat commonly done. Often, when guitarists want to hear their amps and engineers want to be able to have the dry signal, they take the dry signal and then send it to the guitarists Amp. Then they also mic the amp. This gives you the best of both worlds. If the recording of the guitarists amp turns out to be awesome, you're done. If not, you can make changes by either re-recording the guitarists amp or using an in the box effect like TH2 to augment it.

It could happen depending on routing. If the clean signal is slightly ahead of the affected signal check the interface direct monitoring setting.