Setting a timetable helps, but remember it's a guideline only. You don't want to start pressuring yourself to stick to a guideline, because if you fall behind any, you're going to feel you have to catch up, and you don't ever want to make collecting a set feel like "a job". When you stop having fun doing something, you are far less likely to finish. I have that same timeline myself of 10 years, but I know it will be longer, because there are a lot of other cards I want, both pre-war and vintage. I also will continue buying my modern cards. I'll never give them up completely, but I will buy them in smaller quantities.
My advice? Take as much time as you need to feel comfortable. The Monster isn't going anywhere. He's like the damned dragon in the second Hobbit movie. The Monster will sit there and sleep until you're ready to do battle.
You want to educate yourself. Whatever you think you know, you need to know more to best attack this set.
First, I would invest the $15 to buy Bill Heitman's "T206 the Monster" if you find it on eBay.
This was published in 1980. Of course, some of the information has since been updated, but this is a great source to refer to when you have questions about which backs each card has, and which print group a card was part of.
I would also recommend David Cycleback's
Judging the Authenticity of Early Baseball Cards. That's a link to the book on his website. I bought it on Amazon, because I like to be able to carry it with me. This book will help you learn how to identify when cards were printed. It talks about the printing technology used prior to 1930, and how it looks under high magnification. This is good education for anybody that plans on buying pre-war baseball cards.
Once you have these, you want the rest of your startup kit. You need to get yourself a good magnifying glass, or jeweler's loupe. I use a nice Bausch and Lomb 10 x loupe. You can get one for $10 or so. If you find one you like that has a light source, that would be worth paying a little more money.
Get yourself a black light. David goes over black light in his book. That will help you discover a myriad of restoration jobs that you wouldn't otherwise be able to see in normal lighting conditions. If you buy a card, you want to make sure it's not hand trimmed. The loupe will help with that. You want to make sure that paper has not been added to the card, that chemicals haven't been used to clean the card, and that nothing has been done to recolor the card. Any of those will show if you send a card in for grading. That will result in your getting an "auth" grade back.
You also want a good, strong lighting source to be able to examine both sides of a card under. I believe the best kind is referenced in his book, as well.
When it comes time to start buying, start out by buying some inexpensive cards. Actually, if you can buy a beater T206, do it. It will be cheap, and you can learn from it. If there are rough edges and corners, you will get a good idea what the paper looks like. If you have one of those flat edge razor blades, use it to trim one of the sizes of the card. Then, with your loupe, look at that new edge, and then examine the other edges. You want to learn early on how to identify trimmed edges. There is a good primer at the top of the forum page, listed as "detecting card alterations and reprints". Read that thing all the way through.
I'd suggest your next T206 should be a nice ungraded common, purchased here on the BST. You don't need to spend more than $30 on it, because you're not looking for a show stopper. Just a nice card you can compare other cards to. When you are considering buying a card, if you can look at it up close before buying, compare it to your base card under the lopue. You should be able to tell if the card is real, or a reproduction. Then, check the edges and corners. Look for uniform wear. Cards with uneven wear is often an indication of card alteration. For a while, it's good practice to keep comparing your cards to this second card that you bought. Eventually, you'll be able to look at a card, and know if it's authentic, or something else.
The majority of the T206 cards I buy are from our BST here because I can look to see if somebody has sold cards here before. Most of the people I buy from, I already know. But for newer people, I can ask anybody that has done business with them before. The people I've traded with I list in my signature. But whenever I buy a T206 card, or any other pre-war card, or a vintage card, I only buy from trusted sources. You will learn over time which eBay sellers are trustworthy. If you're not sure, ask. A quick search of the user's name on our forum will help you find information about them.
The best advice I can give you is to buy from people that you trust. By doing so, you greatly lessen the likelihood that you are getting an inauthentic card. Remember that even trusted people will sometimes make mistakes. If a seller has a lot of inventory changing hands, sometimes things will slip through. The few times I've seen that happen, the seller has immediately acted to resolve the situation.
Always have a healthy skepticism. By knowing there are people out there that would try to take advantage of good, trustworthy hobbyists, you are already ahead in the game. Bottom line, though, if you are unsure of something, don't hesitate to ask the members of this forum for help. When I'm looking for something, I will use the search function here on the forum, or on Google. There I type in the forum name, and what I am looking for. If I can't find what I'm looking for, or the information is outdated, I will start a topic on the appropriate board, and get some help there.
Have fun, and good luck! Remember, the Monster wants you to quit. You should have patience as you build the set. There's no rush. If you can afford to buy some of the more expensive cards, once you feel comfortable with the cards, you would do well to buy some of them. They will continue to go up in value, and generally at a faster rate than the commons. So, you will ultimately save yourself some money by buying them now.
Feel free to message me if I can help you with anything.
Bill