There will always be more to learn in the investment world: innovation is always happening and the products will change along with market conditions. Bonds are no exception.
The bond market is huge — actually larger than the stock market, if you can believe that — and there are literally hundreds of economic, market, and tax-related factors which influence the decisions of which bonds to buy.
You must look at the yield curve, duration, rating of the issuer, your own cash flow needs, expected changes in the interest rate environment, changes in the overall health of the economy, tax implications, account in which you're buying bonds, and so forth. Therefore, structuring fixed income accounts is a task which is perhaps better left to professional advisors.
We advise you to strongly consider seeking a professional opinion regarding your own situation before buying individual bonds.
Do I Need a Financial Advisor?
What are Bond Ratings?
What Types of Bonds Are There?
How Do I Structure My Bond Portfolio?