Tạo một widget Html/Javascrip ở phần footer. sau đó dán đoạn code bên dưới vào.

Demo

<table border="0" cellpadding="0" cellspacing="0" width="100%">

  <tbody><tr>
    <td><img style="width:83px; height:99px" alt="" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgnUVRJAgnsNTG3_pxIrhlzk_uC6Da2NrYfI7z5E1OcXgkQmbjZPYUExmeDBoTMeAv-j1GIrWyM7mkjlNj6YmhqRUtaESICVTD8tt-LNht8zbtkSP_5JREwG_H8SLKVvDTYF4Y0ZXvzPBE/" align="" border="0" /></td>
    <td>     <div style="background: none repeat scroll 0% 0% rgb(225, 225, 225); border: 0px solid rgb(202, 207, 168);">



<script language="javascript">var leftrightslide=new Array()
var finalslide=''
leftrightslide[0]='<a target=\"_blank\" href=\"http://www.vnews247.co.cc\"><img style=\"\" alt=\"\"src=\"https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEXADzjp-Wa6G7Tmbv9Usuvt-XCm1gjpB3DoR2XlkLSQWogu_Jp9BPkZuW7Nu9uipDB2F9Oz5NuM_qA-3sUCfp0kOImagPRZT2gFcT4dM4jOk6mXyNet8hQuezg_-gknDyoCF9hmkOvVXO/\" alt=\"\" align=\"\" border=\"0\"></a><a target=\"_blank\" href=\"http://www.mailienpham.co.cc\"><img style=\"width:; height:90px"\" alt=\"\" src=\"https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiLZddnjtTrQu6Fd-AL3YuuML11RBhUoQORInXN5sFI-eaQurPsL834n-GxetjUnPgjXkk_dE_EkWqzeKiJuyPjt0R2wyxlUyjVXTQXb0Dgrvt3ZKo1TFvEagVnerNQJk1azeBI0rcBeWo/\" align=\"\" border=\"0\"></a><a target=\"_blank\" href=\"http://www.vn-s.tk\"><img style=\"width:90px; height:90px"\" alt=\"\" src=\"https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg2rNc8YnZ217tLowv9TJnexXiNM5mzWfFXna8kLnAIyudEFrW6IxGYYgwMd0Zngb5PlNhXUrVphr4rnnkXwtLMV08tMg9vB17HlmHkt1V_8Zs7TN-8ptC1_u-pd_aXGAaIe-KfqwWF7Czw/s320/125x125-vns.jpg\" align=\"\" border=\"0\"></a><a target=\"_blank\" href=\"http://www.blog24h.tk\"><img style=\"width:; height:90px"\" alt=\"\" src=\"https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2kU_H56wS1uLB2KfzmOp3H3dSLUXg5w5o8h_E-LZHJIA2APx1qvjIG4bKkpJK5N_MPEjvEqx9r1JLMe4PdnjIhPNWEcGLyp4Nxwfeyp8RbSq0uJzuiuqRnB0QIZfkGU7bm9BXAXri04iE/s320/180x100-blog24h.jpg\" align=\"\" border=\"0\"></a><a target=\"_blank\" href=\"http://docsach-online.blogspot.com\"><img style=\"width:90px; height:90px"\" alt=\"\" src=\"https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh99HIVNJ-vMUI8R8-rcOtXIWCoLXLYYslFw_TpkIal_8TWKf-7gY3QLJmOnlQHaY_PUxV91i8H9OB1bAFQyOJ0ZjI3O9c10BjdirYy01SYki_CQ_teL9UD-rYR5DN57jnShHYkR7Eh-Mng/s320/docsachonline.jpg\" align=\"\" border=\"0\"></a><a target=\"_blank\" href=\"http://mm247.blogspot.com\"><img style=\"width:90px; height:90px"\" alt=\"\" src=\"https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjeJcELD7-v0njO9v5RMSpe861fOOBy7SIstchyphenhyphenlIdFSOBSwOhyH6aNnOhJYWzZypW4tm3ICir5Ov-vNEIdAFGmIl-cNlllJuv-gXSlZgAY_hcWX8pOupTz3ay95nfl9xqQOoJp7qyZ1a8X/s320/125x125-247.jpg\" align=\"\" border=\"0\"></a><a target=\"_blank\" href=\"http://ngolich.blogspot.com\"><img style=\"width:; height:90px"\" alt=\"\" src=\"https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjfR0H2dwUgC3XV4OX8mFX0rynEvQbQEWwDcTTU1GCaSHqxFt9TL_cigPpnKPU1X0K2RK2SSYuUTl3CdLM_86XSjDFpvIN-2b3ca1VCYR5VnZ3uzO2boaSzFAOXdHrfoPZdQMc4QdleYHmO/\" align=\"\" border=\"0\"></a><br><br>';
   

</script>

<script language="javascript" src="http://dohoang.googlecode.com/files/logo.js"></script></div></td></tr></tbody></table>
Chỉnh sửa kích thước logo tại đây : img style=\"width:90px; height:90px"\"
Thay hình ảnh mà bạn muốn vào đoạn code màu đỏ. Địa chỉ liên kết ở đoạn code màu xanh.
Nếu muốn thêm logo thì các bạn thêm đoạn code như thế này :
<a target=\"_blank\" href=\"http://www.vnews247.co.cc\"><img style=\"\" alt=\"\"src=\"https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEXADzjp-Wa6G7Tmbv9Usuvt-XCm1gjpB3DoR2XlkLSQWogu_Jp9BPkZuW7Nu9uipDB2F9Oz5NuM_qA-3sUCfp0kOImagPRZT2gFcT4dM4jOk6mXyNet8hQuezg_-gknDyoCF9hmkOvVXO/\" alt=\"\" align=\"\" border=\"0\"></a>
Lưu ý tùy theo kích thước của Blog bạn mà chỉnh sủa file scrip cho phù hợp :  http://dohoang.googlecode.com/files/logo.js
Save lại là xong chúc bạn thành công .